keep a weather eye out

keep a weather eye out

An instruction to monitor someone or something, often because the person or thing in question may turn out to be dangerous. I think Tom's a thief, so keep a weather eye out around him. I'd keep a weather eye out with this storm that's brewing—we may have to evacuate.
See also: eye, keep, out, weather
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

keep a weather eye out

Also, keep a weather eye on or open . Be extremely watchful or alert, as in We should keep a weather eye on our competitors in case they start a price war. The precise allusion in this expression is disputed, but presumably it refers to watching for a storm. [Early 1800s]
See also: eye, keep, out, weather
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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