脇 is a Japanese kanji written with 10 strokes, listed here under the keyword “armpit”. It is built from 劦 (triceps) and 月 (month). In Remembering the Kanji by James W. Heisig it is frame 935.
On KumiJi Glyph Explorer, open the parts search and type “triceps” + “month”. 脇 is among the results, together with every other character containing the same shapes.
Open 脇 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.