Senses
芥 mustard (jiè)
(bound form) mustard; variety of related leafy vegetables; can also refer to mustard seeds or powder used as a spice
芥 small grass
(bound form) tiny blade of grass; used figuratively to describe something trivial or insignificant
芥 mustard (gài)
(bound form) pronunciation used in specific plant names such as 芥蓝 (Chinese broccoli) or 芥菜 (leaf mustard)