徒あだし心ごころ

noun

cheating heart; fleeting heart; fickle heart

Archaic noun describing a heart that is unfaithful, changeable, or easily swayed in love. Found in classical literature; not used in modern everyday speech.

• 古こ典てん和わ歌かには「徒あだし心ごころ」という言こと葉ばが恋こいの儚はかなさを表あらわすのに使つかわれる。

  In classical waka poetry, the word 徒し心 is used to express the fleeting nature of love.