사수 (sasu)

사수 (sasu) means “guarding something with your life on the line.” In hanja it’s 死守 — 죽을 사 (死), the character for “die,” joined to 지킬 수 (守), the character for “guard.” Going by the characters alone, this is pure battlefield language. And yet the place where Koreans say this word most often today is not a battlefield. It’s a picnic mat spread out on the riverbank at a fireworks festival, or the bank balance at the end of the month, or the screen where you put in for your summer vacation days.

Study Korean long enough and you’ll keep meeting words like this: words that are heavy and grim by origin, which people then lay deliberately on top of something trivial because they know exactly how heavy the word is. The joke only lands if you feel the weight — which is precisely what makes a word like this fun for learners.

Three things sit underneath 사수. First, there is someone trying to take it from you. Second, there is nowhere to fall back to. Third, you’ve accepted the cost. When all three are in place, it’s 사수; take away even one and it’s just 지키다 (jikida), plain “to protect.” That’s why the word becomes resolve in a serious setting and comedy in a silly one. The moment someone answers a request to save a seat with “목숨 걸고 사수할게 (moksum geolgo sasuhalge)” — “I’ll defend it with my life” — they have promoted a single picnic mat to the rank of fortress.

Checking it in the National Institute of Korean Language dictionary

The National Institute of Korean Language’s Basic Korean Dictionary explains 사수 this way:

사수 (noun) — 목숨을 걸고 지킴. 어떤 것을 지키기 위하여 목숨을 내걺. [en] desperate defense; guarding someone with your life; protection; securing — The act of risking one’s life to protect something. [ja] ししゅ【死守】 — 命がけで守ること。 [es] acción de defender algo arriesgando la vida — Acción de defender algo arriesgando la vida. [zh] 死守，誓死捍卫 — 拼命守卫。 — National Institute of Korean Language, Basic Korean Dictionary (krdict.korean.go.kr)

(The dictionary carries no Portuguese translation, so we’ve supplied one for reference — ato de defender algo arriscando a vida. That single line is our own translation, not dictionary text.)

Here are the real usage examples the dictionary lists alongside the entry.

전쟁에 참가한 군인들은 조국 사수를 다짐하며 적을 향해 돌진했다. (jeonjaenge chamgahan gunindeureun joguk sasureul dajimhamyeo jeogeul hyanghae doljinhaetda.) The soldiers who had joined the war charged at the enemy, vowing to defend their homeland to the death.

그 회사의 공장 건립을 반대하는 주민들은 마을 사수를 외쳤다. (geu hoesaui gongjang geollibeul bandaehaneun jumindeureun maeul sasureul oechyeotda.) The residents opposing the company’s plan to build a factory cried out that they would defend their village. — National Institute of Korean Language, Basic Korean Dictionary (krdict.korean.go.kr)

The first sentence is the word’s birthplace. Soldiers, homeland, a charge — it shows you the original temperature of 사수. Here the word isn’t a metaphor at all; it’s literal.

The second sentence matters much more. This is 사수 stepping out of war and into an everyday conflict. The residents have no guns, but if they lose the village, their lives collapse. In Korean news, this is usually the kind of scene where 사수 shows up — redevelopment sites, factory land, campaigns against school closures. When there’s a force trying to take something and no room to back up, people reach for 사수 instead of 지키다.

The dictionary also shows which verbs the word travels with.

사수를 하다. (sasureul hada.)

사수를 외치다. (sasureul oechida.)

사수를 다짐하다. (sasureul dajimhada.)

사수를 약속하다. (sasureul yaksokada.)

사수를 고집하다. (sasureul gojipada.) — National Institute of Korean Language, Basic Korean Dictionary (krdict.korean.go.kr)

Sit with that list and a pattern appears. 외치다 (oechida) “to shout,” 다짐하다 (dajimhada) “to vow,” 약속하다 (yaksokada) “to promise” — every one of them is a verb of saying something out loud. 사수 isn’t something you do quietly inside your head; it’s something you declare. That’s how it becomes a chant, a pledge, and a punchline. The last one, 고집하다 (gojipada) “to insist on,” has a different grain: it carries a hint that you’re clinging alone to something everyone else thinks you should have let go of already.

In actual conversation, the bare noun is far less common than the verb form 사수하다 (sasuhada). 사수를 하다 → 사수하다, 사수할게 (sasuhalge), 사수하겠습니다 (sasuhagetseumnida).

Seeing it in a real conversation

Scene: the afternoon of the Yeouido fireworks festival. You’ve been sitting on a mat by the river for three hours now, holding your spot. The crowd keeps swelling, and plenty of eyes are scanning for an opening.

Jun-kyung: 나 화장실 좀 갔다 올게. 자리 좀 사수해 줘. I’m going to run to the restroom. Hold down our spot for me.

Emily: 걱정 마. 목숨 걸고 사수할게. Don’t worry. I’ll defend it with my life.

Jun-kyung: 오버하지 마… 근데 진짜로 저 아저씨들 아까부터 이쪽 계속 봐. Don’t overdo it… but seriously, those guys have been eyeing this spot for a while.

Emily: 봤어. 그래서 돗자리 네 귀퉁이에 가방이랑 신발 다 올려놨잖아. I noticed. That’s why I put our bags and shoes on all four corners of the mat.

Jun-kyung: 오, 프로다 진짜. Whoa, you’re a total pro.

Emily: 15년차야. 나 명절 기차표도 사수한 사람이야. Fifteen years here. I’m someone who managed to secure holiday train tickets, you know.

Using it this way sounds off

✗ 친구가 준 인형을 10년 동안 사수했어요. (chinguga jun inhyeongeul sim-nyeon dongan sasuhaesseoyo.) ✓ 친구가 준 인형을 10년 동안 소중히 간직했어요. (chinguga jun inhyeongeul sim-nyeon dongan sojunghi ganjikaesseoyo.) I’ve treasured the doll my friend gave me for ten years. → 사수 always presumes someone trying to take the thing from you. Keeping an object nobody is after for a long time isn’t 사수, it’s 간직 (ganjik), “treasuring.” Otherwise it sounds like you built a fortress with no enemy in sight.

✗ 제가 할머니를 사수하겠습니다. (jega halmeonireul sasuhagetseumnida.) ✓ 제가 할머니를 지켜 드리겠습니다. (jega halmeonireul jikyeo deurigetseumnida.) I’ll look after my grandmother. → The objects of 사수 are things that get seized and re-seized: seats, land, records, rankings, standards. Attach it to a person and you make them sound like a corner of a trench or a piece of loot — so an attempt to say “I care about you” comes out rude instead. For people, use 지키다 (jikida) or 보호하다 (bohohada).

Example sentences by situation

1. A quarterly earnings meeting — declaring your resolve in earnest

이번 분기 시장 점유율 1위는 무슨 일이 있어도 사수하겠습니다. (ibeon bungi sijang jeomyuyul il-wineun museun iri isseodo sasuhagetseumnida.) We will hold on to our number-one market share this quarter, no matter what.

Put 사수 in front of a number and it carries far more grit than “we’ll maintain it.” It fits naturally when a competitor is right on your heels — that is, when the party trying to take it away is clearly visible.

2. End of the month, texting a friend — exaggerating for laughs

이번 달은 진짜 통장 잔고 사수한다. 약속 다 취소야. (ibeon dareun jinjja tongjang jango sasuhanda. yaksok da chwisoya.) This month I’m seriously defending my bank balance. All plans cancelled.

The enemies coming for your bank account are delivery apps and friends. There’s an opponent, and if you retreat the balance hits zero — exactly the conditions for 사수. That overstatement is the whole joke.

3. The day after a concert ticket sale — fans talking among themselves

앞줄 사수하려고 알람 세 개 맞춰 놓고 잤어. (apjul sasuharyeogo allam se gae matchwo notgo jasseo.) I set three alarms before bed just to secure a front-row seat.

Ticketing in Korea really is a war fought in seconds, so here 사수 is barely an exaggeration at all. In fandom language, 자리 사수 (jari sasu), “defending your spot,” is a set phrase.

Politeness levels and similar expressions

사수 is a noun, so the politeness comes from the ending attached after it. The same resolve splits like this depending on the setting.

Casual: 사수할게 / 사수한다 (with friends, or muttering to yourself)
Polite everyday: 사수할게요 / 사수하려고요 (with coworkers; light formality)
Formal: 사수하겠습니다 (reports, official occasions, chants)

Lining it up against its neighbors makes its position clear.

Expression	Temperature / intensity	Where it’s used
사수하다 (sasuhada)	Maximum grimness. A word of resolve and declaration	Protest chants, earnings reports — and jokes that overstate on purpose
지키다 (jikida)	Neutral	Promises, secrets, people, rules — almost any object
고수하다 (gosuhada)	Stubborn; can look pig-headed from outside	Positions, principles, methods — things you can’t see
보호하다 (bohohada)	Calm and official	Vulnerable subjects; frequent in legal and institutional documents

The same situation paints a different picture depending on which word you pick. 원칙을 지킨다 (wonchigeul jikinda) is plain and matter-of-fact; 원칙을 고수한다 (wonchigeul gosuhanda) is stubborn; and 원칙을 사수한다 (wonchigeul sasuhanda) means you’ve braced yourself to lose something for the sake of that principle.

Cultural background — the four corners of the mat

Just as the characters 死守 suggest, this word’s hometown is the army and the battlefield. In Korean news, 사수 still lives in weighty places: banners on the walls of redevelopment districts, residents rallying to stop a school from closing, the “3위 사수 (sam-wi sasu)” — “defending third place” — of a pro baseball broadcast during a standings fight. The dictionary’s 마을 사수 (maeul sasu), “defending the village,” is alive and well in today’s papers.

At the same time, the word has come down broadly into daily life. For office workers, 여름휴가 연차 사수 (yeoreum-hyuga yeoncha sasu) — defending your summer vacation days — is a project for the whole year; the day holiday train tickets go on sale is a national day of 사수; and a picnic spot by the Han River in cherry blossom season is defended by planting a bag on each of the mat’s four corners. Korean dramas are full of scenes like this too. In a show set in a neighborhood being pushed out by redevelopment, the moment where residents gather at the mouth of an alley and dig in with “we’re not giving this up” will feel familiar even without the exact lines. Compress that scene into one word and you get exactly 사수.

One word of caution. If you hear someone at a Korean company say “제 사수예요 (je sasu-yeyo),” that is a different word from the 死守 you learned today. It’s workplace vocabulary for the senior employee who trains a new hire, and its counterpart is 부사수 (busasu), the junior. Same sound, completely different meaning — so when this word comes up in the office, don’t hear it as “guarding with your life.”

Today’s quiz

Which of the following uses 사수 most naturally?

어릴 때 쓰던 일기장을 서랍에 사수하고 있어요. I’m 사수-ing the diary I kept as a kid in my drawer.
마감까지 사흘 남았지만 이 디자인 콘셉트만은 사수하겠습니다. We have three days to the deadline, but I’m 사수-ing this design concept if nothing else.
오늘 날씨가 좋아서 공원을 사수했어요. The weather was nice today, so I 사수-ed the park.

Show the answer

Answer: 2

Number 2 has every condition for 사수: the pressure of a deadline (the force trying to take it), a situation with nowhere to retreat when people demand the concept be changed, and the readiness to pull an all-nighter. Number 1 involves an object nobody is after, so 간직하다 (ganjikada), “to keep, to treasure,” is the right word. Number 3 has no object that can be defended or seized in the first place, so the sentence doesn’t hold together at all.

Definitions and example sentences are from the National Institute of Korean Language’s Basic Korean Dictionary (krdict.korean.go.kr); that portion of this post, including our translations, is licensed under CC BY-SA 2.0 KR.