Canada, US A small nail-like tack with a slightly rounded head that can be pressed into place with light pressure from the thumb; used for hanging light articles on a wall or noticeboard.
You say that I'm broke my nigga, how is that? Bitch I'm stickin to this paper like a thumbtack2016 June 10, BlocBoy JB, “No Chorus, Pt. 5”, in Who Am I, 1:20–1:27:
thumbtack
verb
Etymology From thumb + tack.
1
To fix or attach something with a thumbtack.
On the particle-board partition that separated his cubicle from the next, Paul had thumbtacked things that might inspire him […]1988, Edmund White, chapter 1, in The Beautiful Room is Empty, New York: Vintage International, published 1994: