- Alternative form of
- (idiomatic) To add something extra free of charge.
- If you take the large size, we'll throw in a set of tea towels.
- (idiomatic) To quit, to fold.
- (idiomatic) to include in a calculation
2018 March 1, Anthony Zurcher, “Trump addresses Congress: A kinder, gentler president”, in BBC News:
- Throw in Mr Trump's promise of a "great, great wall along our southern border" - with estimates starting at $12bn - and "massive tax relief for the middle class", and the price tag for his speech proposals is on an express elevator to astronomical.