Meaning of “pin sth up” - Learner’s Dictionary

pin sth up

phrasal verb with pin uk us /pɪn/ verb [ T ] (present participle pinning, past tense and past participle pinned)

to fasten something to a wall using a pin:

The exam results have been pinned up on the noticeboard.

(Definition of “pin sth up” from the Cambridge Learner’s Dictionary © Cambridge University Press)