Idioms and Phrases with pit against
Set in direct opposition or competition, as in The civil war pitted brother against brother. This idiom alludes to setting fighting cocks or dogs against one another in a pit. [Mid-1700s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.