生温い
なまぬるい · namanurui · JLPT N1 · i-adj
lukewarm
🍵 生 (raw, half-done) + ぬるい (lukewarm) = half-warm, which also gives halfhearted
生 means raw or not fully done, so 生ぬるい means not fully warm. The same half-done sense gives the halfhearted meaning.
生 — sprout 屮 above earth 土
Originally a pictograph showing a young plant sprouting from the ground, with 屮 (a sprout) above 土 (earth). The core meaning is 'to be born, to grow, to live,' which extends to 'raw, unripe, unfamiliar.' The modern form has simplified the sprout shape but preserves the image of new growth emerging from soil.