訓 くる(しい),にが(い) ・ 音 ク
漢越音: khổ
艹 (grass, plants) for meaning, 古 (old) for sound: a bitter-tasting herb. From bitter on the tongue to bitter in life — suffering, hardship.
Stroke data: KanjiVG (CC BY-SA 3.0) — kanjivg.tagaini.net
数学は苦手です。 (すうがくはにがてです)
I am not good at math.