Hairpin
From Memory Alpha, the free Star Trek reference
A hairpin is a Human device women use to keep their hair in place.
Nurse Faith Garland had a hairpin in her hair. As his universal translator was broken, Rom gestured toward her hair while asking for it in Ferengi. She gave it to him, and he used it to work on Nog's translator, which Garland observed looked painful. (DS9: "Little Green Men")
In Julian Bashir, Secret Agent, Doctor Bashir, playing his role as Patrick Merriweather, used his charm to convince Doctor Honey Bare (who was imbued with the body of Jadzia Dax by accident) to give him her hairpin. He then used it to undo the handcuffs binding him and Elim Garak at the time. (DS9: "Our Man Bashir")
