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]

Words nearby keep a weather eye out

keep a civil tongue in one's head, keep a low profile, keep a sharp lookout, keep a stiff upper lip, keep a straight face, keep a weather eye out, keep abreast of, keep after, keep an eye on, keep an eye out for, keep at