Also found in: Dictionary, Thesaurus, Encyclopedia.
To start participating in something; to join. Come on, Davey, join in the fun. Just because the other kids were making fun of him doesn't mean you should have joined in.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
join in (with something)
to participate in doing something. The older boys joined in with the singing. I'm glad they joined in. We needed basses.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
To take part in something; participate in something: The tenors started singing, and then the sopranos joined in. The adults joined in the celebration.
The American Heritage® Dictionary of Phrasal Verbs. Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.