noun

the action or fact of dying or being killed; the end of the life of a person or organism.

he had been depressed since the death of his father

demise,dying,end,passing,passing away,passing on,loss of life,expiry,expiration,departure from life,final exit,eternal rest,murder,killing,assassination,execution,dispatch,slaying,slaughter,massacre,snuffing,curtains,kicking the bucket,decease,quietus