空腹
くうふく · kuufuku · JLPT N1 · noun
hunger
🍽️ 空 = empty + 腹 = belly: an empty belly means hunger
Pronounced kuufuku. 空 (kuu) means empty and 腹 (fuku) means belly, so the word literally says empty belly, the same idea as the English term empty stomach.
空 — cave radical 穴 + 工 (phonetic)
Originally a phono-semantic compound: 穴 (cave, hole) gives the meaning of emptiness or hollow space, while 工 supplies the sound. The earliest sense was 'hole' or 'cavity,' which extended to 'empty,' 'sky,' and 'in vain.' The reading kòng (4th tone) specifically means 'free time' or 'vacancy.'