See also: letin
- (transitive) To let someone or something come in; to admit someone or something in.
- He opened the window to let in the air.
- (transitive, Oxford University slang) To associate with.
- 1859, Hughes, Thomas, chapter 1, in Tom Brown at Oxford:
- He has also been good enough to recommend to me many tradesmen who are ready to supply these articles in any quantities; each of whom has been here already a dozen times, cap in hand, and vowing that it is quite immaterial when I pay—which is very kind of them; but, with the highest respect for friend Perkins (my scout) and his obliging friends, I shall make some enquiries before "letting in" with any of them.
to let someone or something come in