扣眼

eyelet / buttonhole

to fasten / to button / button / buckle / knot / to arrest / to confiscate / to deduct (money) / discount / to knock / to smash, spike or dunk (a ball) / to cover (with a bowl etc) / (fig.) to tag a label on sb / (Tw) (loanword) code

button

eye / small hole / crux (of a matter) / CL:隻|只[zhi1],雙|双[shuang1] / classifier for big hollow things (wells, stoves, pots etc)

erhua variant of 釦眼|扣眼[kou4 yan3]