薬
ヤク, くすり, み

medicine, chemical, enamel, gunpowder, benefit

JLPT3 G3 S16 F702

As per 樂# (acorns) + 艸 grass/plant → grind acorns into a paste-like consistency → *medicine*; *drug* (← finely ground acorns, seeds, roots etc. used for medicinal purposes).

[Full Kanji Etymology List]