C2 adjective /ˌpluːˈpɜːrfɪkt/
pluperfect
過去完了形
Meaning
a verb tense expressing an action completed before another past action
Example
By the time she arrived, he had finished his homework, showing the pluperfect tense.
彼女が到着したとき、彼はすでに宿題を終わらせており、過去完了形を示しています。