noun
pushpin; thumbtack; drawing pin
A small pin with a flat head, pushed into a surface to attach paper or light items. It is Kansai dialect, but it is widely understood.
See also: 画鋲
カレンダーを押しピンで壁に留めた。
I pinned the calendar to the wall with a pushpin.
押しピンが足りないから、買ってきて。
We're out of pushpins, so please buy some.