1
general::
1. Contribute one's share, as in We'll kick in half if you take care of the rest. [Colloquial; c. 1900] 2. Also, kick off. Die, as in No one knows when he'll kick in, or He finally kicked off yesterday. [Slang; first half of 1900s] Also see KICK THE BUCKET. 3. Begin to operate, as in Finally the motor kicked in and we could get started. This usage was first recorded in 1908.
American Heritage Idioms
2
general::
Phrase(s): kick something in
1. to break through something by kicking. • Tommy kicked the door in and broke the new lamp. • He kicked in the door by accident. 2. Go to kick something in (on something) (for someone or something)., Phrase(s): kick in (on something) (for someone or something)
Fig. to contribute to something for someone or something. • Would you like to kick in on a gift for Joel? • I’ll be happy to kick in on a gift. • Sure, I would like to kick in for the gift., Phrase(s): kick something in (on something) (for someone or something)
to contribute something, such as money, on something for someone or something. • I will kick a few bucks in on some flowers for the receptionist. • I will kick in a few bucks on the gift for Marge.
McGrawhill's American Idioms And Phrasal Verbs