Hairpin can mean:*Hairpin (fashion), a long device used to hold a person's hair in placeHairpin turnHairpin cotter, a formed wire fastener most commonly used in clevis pinsHairpin clip, a formed wire fastener designed for use in grooved shaftsA stem-loop in biochemistryHairpins, a 1920 film, directed by Fred NibloHairpin, in music, the nickname for crescendo and decrescendo markings. See Dynamics (music)#Gradual changes… (More on Hairpin)