past it

Prepositional phrase

informal

(informal) No longer capable, not as effective as previously. / (informal) Too old to participate in something.

Japanese Meaning

もう十分に機能しなくなった状態（能力が衰え、以前の効果や活力が失われた） / 参加するには年齢や時期が過ぎたため、もはや適任でない状態

Everyone could tell the old singer was past it, but she still gave her heart on stage.

年老いた歌手は全盛期を過ぎているのが誰の目にも明らかだったが、それでもステージでは心を込めて歌った。

Sense（1）

(informal) No longer capable, not as effective as previously.

Sense（2）

(informal) Too old to participate in something.