면 죽이다

do that and I'll kill you

A condition with -(으)면 plus 죽이다 "kill" is the shape of a threat, and most lines here are exactly that, usually mock ones between friends: 핫도그 가격을 올리면 죽여버리겠어!, '형수님' 인사해, 아니면 죽인다. Note the slang sense in one line — 환갑잔치하면 죽이겠는데 여기? means this place would be *killer* for a sixtieth birthday party, praise rather than menace. 죽다 is to die; 죽이다 is to kill someone, or in slang to be outstanding.

Register: rough, casual