From Longman Dictionary of Contemporary Englishunder the weatherunder the weatherinformalMIILL slightly ill You look a bit under the weather. → weather
Examples from the Corpus
under the weather• And young Curtis has been a bit under the weather, missed training this week, so he's out.• I hear you've been a bit under the weather. Are you feeling better now?• Although he was not as ill as he had made out to Elaine, he still felt a bit under the weather.• You will have off days when you are tired or a bit under the weather.• It was too early in the trip for a serious attempt and all of us were decidedly under the weather.• I began to feel under the weather on Thursday morning after leaving Haslemere.• Like our own, Botham's finances are a little under the weather.• Mike's feeling a little under the weather so he couldn't come tonight.• Louise looked a little under the weather when I saw her.• Marie's pretty under the weather for the next couple of days. 