Be very friendly, as in He is always wanting to buddy up with me, but I don't really like him. [Slang; early 1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
How to use buddy up in a sentence
All we need is somebody to buddy up to him, and take him out there.Shock Absorber | E.G. von Wald