warn about

warn about (someone or something)

1. To provide information in advance about the risks or dangers associated with someone or something. Analysts have been warning about a likely downturn in the economy for months now, so this dip in the market shouldn't come as a surprise. Police are warning about a number of escaped inmates who are at large in the area.
2. To caution someone about someone or something; to inform someone about the risks or dangers of someone or something. In this usage, a noun or pronoun is used between "warn" and "about." My mom always warns me about the dangers of texting while driving. You need to warn him about Allison before he falls prey to her usual tricks.
See also: warn
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

warn someone about someone or something

to advise someone about the dangers associated with someone or something. Didn't I warn you about the dangers of going there? I warned you about Alice.
See also: warn
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

warn about

1. To make someone aware of the actual or potential harm, danger, or evil associated with something: I warned the kids about riding their bikes in the street.
2. To make aware in advance of some actual or potential harm, danger, or evil: The report warned about a possible attack.
See also: warn
The American Heritage® Dictionary of Phrasal Verbs. Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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References in periodicals archive ?
Maintaining her claim, she reports that "[i]n indirect speech, one can warn that, warn about, warn of, warn off, warn not to (do something) or warn to (do something)." In this study, warning refers to the different strategies used for getting the attention of the addressee and making him/her alert to a specific danger or bad consequences.
Early warning is obviously more focused on strategic than on tactical warning and, if as envisaged, will also in future warn about for instance potential terror attacks on African countries and will have to increasingly rely on warning intelligence.
They argued that the distillers had failed to warn about the dangers of drinking during pregnancy.