English

pigeonhole noun definition in In school topic from the Oxford Advanced Learner's Dictionary

pigeonhole

 noun: In school topic
one of a set of small boxes that are fixed on a wall and open at the front, used for putting letters, messages, etc. in; one of a similar set of boxes that are part of a desk, used for keeping papers, documents, etc. in If you can't come, leave a note in my pigeonhole.