死

dead letter

meaningless writing

waning moon

decapitating oneself

three outs

dying by the wayside

committing suicide (to remonstrate or dissuade one's lord); preparing to die in an effort to dissuade one's lord

death by strangulation; ligature strangulation

氏ね and 市ね are Internet slang

drop dead; go to hell; fuck you

dying alone (esp. of someone who lives alone and dies of natural causes at home without anyone knowing); solitary death

Biology

cell death

saving from the brink of death

Medicine

death from infection

dying of cancer

dying of shame; being so ashamed one wants to die

dying in vain

becoming emaciated and die; wither away

place of death

dying in a lost battle; falling in a lost cause

carrion beetle (any beetle of family Silphidae, incl. burying beetles)

dead weight; dead load; static load

dead horse

Derogatory

stupid horse; useless horse; crowbait

after two outs

Medicine

dead space

dead water