defunct 死的 dead, demised

Those rules of etiquette(礼节) have been  defunct for years.

lethal 致命的 fatal, deadly

deadly 致命的 fatal, lethal

Don't be scared; it's not a deadly wound.

demise 死亡 death, end

The country mourned(哀悼) the president's  demise.

choke 窒息n 使窒息v suffocate, block

My lawn mover has a choke(堵塞) that I have to  adjust frequently.

smother 使窒息 闷死 stifle, suffocate

The murderer smothered his victim with a pillow.

expire 断气 perish

John's driver's license expired last week.

mortal 终有一死的 凡人n

All mortals, however outstanding, are to die  one day.