hair·pin 
/ˈheɚˌpɪn/ noun
plural hair·pins /ˈheɚˌpɪn/ noun [count] 1 : a pin that is worn in your hair ; especially : a pin shaped like a U that is worn to hold your hair in place 2 : an extremely sharp turn in a road that is shaped like a U — often used before another noun ▪ a hairpin turn/curve
