on someone's side

on (one's) side

Supportive or in aid of one or one's idea, plan, intention, etc. We're all on your side, Jerry. We just want to see this issue resolved as quickly and easily as possible. If she's going to win this case, she'll need one heck of a legal team on her side.
See also: on, side
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

on someone's side

In support of someone's views or interests, as in I'm glad you're on my side in this debate, or With the Canadians on our side, we should be able to persuade the Mexicans of a North American policy . [1300s]
See also: on, side
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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