The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with leg up, a
leg up, a
The act of assisting someone, giving someone a boost. For example, Studying with Jane, who knows French history well, will give you a leg up for the final exam. This usage alludes to helping a person get on a horse by getting a foot in the stirrup.
[ First half of 1800s
A position of advantage, as in Because of the advertising campaign, we had a leg up on the competition.