脇明け
1
robe worn by military officials with a round collar, unstitched open sides, and no wrapped fabric along the bottom
See also:
闕腋の袍 (けってきのほう)
2
small opening in the side of traditional Japanese clothing (where the sleeve meets the bodice, below the armpit);clothing with such an opening (usu. worn by women or children)
See also:
八つ口 (やつくち)
Other forms
腋明け 【わきあけ】