残念
ざんねん · zannen · JLPT N4 · na-adj
regret
残念 = remaining (残) + thought (念): a feeling that lingers
残 means left over, as in 残る (to remain). 念 means thought or feeling. Regret is literally the thought that stays behind after things go wrong. Sound hook: zannen ends like a sigh, nen... too bad.
残 — 歹 (bones/death) + 戔 (small/cut, phonetic)
A semantic-phonetic compound: 歹 (bare bones, death) gives the meaning of harm or ruin, while 戔 (two 戈 spears, suggesting cutting) supplies the sound. Originally meant to injure or destroy, later extended to 'remnant, leftover' — what remains after damage.
念 — 今 (now, phonetic) + 心 (heart)
念 is a semantic-phonetic compound: 心 (heart) gives the meaning, while 今 (now) supplies the sound. The original sense was 'what is on the heart right now' — a thought held in mind. From this came the modern meanings 'to think of,' 'to miss,' and 'to recite' (holding words in mind).