chip in

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb intransitive, idiomatic To make a contribution; help in a small way; especially, to pay for a part of something.
• verb intransitive, idiomatic, UK, informal To interrupt a discussion for the purpose of making a comment.
• verb transitive, idiomatic To contribute
• verb intransitive, golf To put a chip shot in the hole.
• verb intransitive, card games To put into the pot the amount of chips or money required to continue.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb contribute to some cause