Jièmo shì Rìběn liàolǐ zhōng chángyòng de tiáoliào.
Mustard is a condiment commonly used in Japanese cuisine.
Tips
usage
芥 has two readings: jiè (mustard) and gài (Chinese kale, 芥蓝). The idiom 心存芥蒂 means to harbor a grievance. 芥蒂 literally refers to a tiny mustard seed stuck in the chest.
register
In the sense 'a trivial thing', 芥 is literary and survives only in set expressions such as 草芥 and 芥蒂, not in everyday speech.
艹 is the grass radical 艸 in compressed top form. It tags 芥 as a plant, specifically mustard greens and the tiny mustard seed, and groups it with 菜 (vegetable), 草 (grass), and 花 (flower).
介 supplies the reading jiè directly with no shift. The same phonetic appears in 界 (boundary) and 价 (price), all clustered around the jie syllable. Its faint sense of something small pressed between also fits a tiny mustard seed.
