From King Dictionary of Contemporary Englishwarningwarn‧ing1 /ˈwɔːnɪŋ $ ˈwɔːrn-/ ●●●S3W2 noun1[countable, uncountable]WARN something, especially a statement, that tells you that something bad, dangerous, or annoying might happen so that you can be ready or avoid itwarning ofa warning of floodswarning aboutwarnings about the dangers of smokingwarning againstThis experience should serve as a warning against complacency.warning toa warning to pregnant women not to drink alcohola warning that grey squirrels are threatening the existence of red squirrels2[countable]WARN a statement telling someone that if they continue to behave in an unsatisfactory way, they will be punishedThe Surrey team were given a warning last year for repeated offences.I’m giving you a final warning – don’t be late again.written/verbal warningTHESAURUSwarning something that you say or do to tell people about danger, or to tell them not to do somethingAll cigarette packets carry a government health warning.She ignored her parents' warnings.The army issued a warning that anyone who was out on the streets after dark was likely to be shot.caution formal an officialwarning or a piece of advice telling you to be carefulCaution: do not install electrical equipment near or around water sources.The video begins with a caution that you must do some warm-up exercises first. tip-off informal a warning that someone is about to do something, especially one given to the police about a crimePolice were called to the hotel after a tip-off.alert a warning to be ready for possible danger that may happen soonTwelve flood alerts have been issued to areas along the River Severn.a fire alertThe ambulance services were on red alert (=they were ready to take action immediately).advisory formal an official warning or notice that gives information about a dangerous situationThe air pollution gets so bad on some days that health advisories are posted at park entrances.caveat formal a warning that something may not be completely true, effective etc. Also used when pointing out that it is important to remember somethingThe woman was offered treatment, but with the caveat that it had only a 30% chance of success.One caveat is that you must take the goods back to the shop within 14 days. There is one important caveat to this argument. COLLOCATIONSverbsgive a warningHe slammed on the brakes without giving any warning.issue a warning (=officially warn people)The government issued a warning about eating raw eggs.deliver/sound a warning (=give a public warning)The chairman sounded a warning that jobs could be lost.heed a warning (=take notice of it)Drivers failed to heed warnings about fog.ignore a warningHe had ignored their warning to stay in the car.ADJECTIVES/NOUN + warningadvance/prior warningWorkers were given no advance warning of the closure.fair warningHe was given fair warning that such behaviour would not be tolerated.a stern warningI got a stern warning against giving false information to the police.a stark warningCigarette packets carry the stark warning ‘smoking kills’.a health warning (=a warning that something is bad for your health)All tobacco products must carry a health warning.a flood/gale/tornado warningA flood warning has been issued for the River Wye in Herefordshire.phraseswithout (any) warningPolice fired into the crowd without warning.a word of warning (=used before telling someone to be careful about something)A word of warning: don’t use too much glue.