To contribute money for a specific purpose or for the good of the group. Informal
The phrase may derive from the act of passing around a hat, into which contributors would "throw in" some money.
Synonyms for throw in
On this page, you will find 30 slang terms related to throw in. Some of the top words include: balling out of control, throw down, Busting, tort, extended stay, and 25 more.