adverb
as a reminder; to help remember
Used when doing something to aid memory, such as jotting down a note or making a mark. Often appears in the phrase 心覚えに書く (write down as a reminder).
忘れないように、心覚えにメモを取った。
I took a note as a reminder so I wouldn't forget.
彼は心覚えに、手帳に簡単な絵を描いた。
He drew a simple picture in his notebook as a memory aid.
Compound of 心 (こころ, 'heart, mind') + 覚え (おぼえ, 'memory, remembering') + に (adverbial particle). The exact historical derivation is uncertain, but it has been used since at least the Edo period to mean 'as a reminder' or 'to keep in mind'.