end (of life); death; demise
(peacefully) spending one's final years
彼は静かな終焉を迎えた。
He met his end quietly.
一時代の終焉が近づいていると感じた。
I felt that an era was coming to its close.
生涯を捧げた研究の終焉を、彼は悲しそうに見届けた。
He watched the end of the research he had devoted his life to with a sad expression.