noun-modifying (irregular)
Describes something heard so often that it has become boring or clichéd. Used prenominally to modify nouns like 話 (story), 冗談 (joke), or セリフ (line).
彼の聞き古した冗談にはもう誰も笑わない。
Nobody laughs at his hackneyed jokes anymore.
そのスピーチは聞き古したフレーズばかりだった。
The speech was full of trite phrases.