at bay - Phrases/Idioms
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.
Cornered, in distress, as in Angry bystanders chased the thief into an alley and held him at bay until the police arrived. This idiom originally came from hunting, where it describes an animal that has been driven back and now faces pursuing hounds. Its use for other situations dates from the late 1500s.