slip away
https://gyazo.com/4d0ded4e30a6a6c05a26ffcfc929ac93
source: Speedwagon withdraws coolly
slip away
depart without saying goodbye; leave quietly or surreptitiously.
(気づかれないように)そっと立ち去る
slowly disappear; recede or dwindle:
〈感情・能力・機会などが〉(次第に)無くなる
e.g. his ability to concentrate is slipping away.
die peacefully (used euphemistically):
(老衰のため安らかに)逝く, 死ぬ (!dieの婉曲表現)
e.g. he lay there and quietly slipped away.
#phrasal_verb