心当たり
こころあたり · kokoroatari · JLPT N2 · noun
having some knowledge of
🎯 心 (mind) + 当たり (hit) = a mind-hit: a clue your mind has landed on
当たる means to strike or hit the mark, as in 大当たり (jackpot). A 心当たり is a clue your mind has hit upon, so you have some idea where something is or who did it.
心 — pictograph of a heart with chambers and aorta
心 is a pictograph showing a stylized heart, with strokes representing the organ's chambers and the aorta at the top. Originally meaning the physical heart, it broadened to cover mind, feelings, and intentions, since ancient Chinese thought located thinking and emotion in the heart.
当 — small ⺌ + crown 冖 + hand 彐 (simplified from 當: 尚 + 田)
Originally written 當, combining 田 'field' with 尚 as a phonetic. The early sense was 'to match' or 'face' a field of equal value, extended to 'correspond to', 'ought to', and 'serve as'. The simplified form 当 streamlines the upper 尚 component.