by heart
成語所屬單字by
by heart — 慣用語
1. remembered perfectly in your memory, so you can repeat it without looking.
1.慣用語
釋義
熟記在心；牢記
remembered perfectly in your memory, so you can repeat it without looking.
例句
Maya knows the lyrics of every Taylor Swift song by heart.
The young actor learned his lines by heart before the rehearsal.