/'pɒpə(r); `pɑpɚ/
n (Brit infml 口) = press-stud (press2).

n
[C]BrE informal a small metal thing that is used to fasten clothes, which works when you press its two parts together
American Equivalent: snap
poppers [plural]informal
an illegal drug in the form of a liquid, which people take for pleasure by breathing it in