Definition of let in
1 : to insert or embed in (a surface) lets in diagonal sheathing at each corner of the house
2 : to involve or commit unfavorably the provisions … could still let us in for trouble — Elmer Davis smiled at all her schemes, little dreaming that … she was letting him in for some £20,000 — Elizabeth Montizambert
3 : to share information with or allow to participate learned a lot more … and I'll let you in on it — Rex Ingamells
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Seen and Heard
What made you want to look up let in? Please tell us where you read or heard it (including the quote, if possible).