Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “warn”

See all translations

warn

verb [I or T] uk   /wɔːn/ us    /wɔːrn/
B1 to make someone realize a possible danger or problem, especially one in the future: [+ obj + to infinitive ] We were warned not to eat the fish which might give us a slight stomach upset. [+ obj + (that) ] Have you warned them (that) there will be an extra person for dinner? I was warned against/off going to the east coast because it was so full of tourists. There were signs warning of fog as soon as we got onto the motorway. This particular curry is extremely hot - be warned! Put that ball down and come over here, Laura - I'm warning you (= I will punish you if you do not)!
More examples
(Definition of warn from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of warn?
Add Cambridge dictionaries to your browser to your website

Definitions of “warn” in other dictionaries

Word of the Day

work out

to exercise in order to improve the strength or appearance of your body

Word of the Day

Byronic, Orwellian and Darwinian: adjectives from names.

by Liz Walter,
April 15, 2015
Becoming an adjective is a strange kind of memorial, but it is often a sign of a person having had real influence on the world. Science is full of examples, from Hippocrates, the Greek medic born around 460 BC, who gave his name to the Hippocratic Oath still used by doctors today,

Read More 

bio-inspiration noun

April 13, 2015
the adoption of patterns and structures found in nature for the purposes of engineering, manufacturing, science, etc. The MIT researchers actually aren’t the only robotics team to turn to cheetahs for bio-inspiration.

Read More