warn against (something)

(redirected from warn him against)

warn against (something)

To caution (someone) not to do something that is dangerous or risky. A noun or pronoun can be used between "warn" and "against." My mother always warned me against hanging out with hoodlums like you, and now I know why. Doctors are warning against spending too much time outside during this week's heatwave.
See also: warn

warn someone against someone or something

to advise someone against someone, something, or doing something. We warned them all against going to the region at this time. I warned her against Gerald.
See also: warn

warn against

v.
To advise someone that something is dangerous or problematic and should be avoided: I warned them against driving without seatbelts. The doctor warns against smoking.
See also: warn