From Longman Dictionary of Contemporary Englishto be on the safe sideto be on the safe sidespokenCAREFUL to do something in order to be certain to avoid an unpleasant situation I’d take an umbrella, just to be on the safe side. → safe
Examples from the Corpus
to be on the safe side• Dougal had arranged to hire it for the Sunday and the Monday, just to be on the safe side.• He cut a lot to be on the safe side.• She must fetch her raincoat, just to be on the safe side.• She says do not worry, but it's wiser to be on the safe side.• Just to be on the safe side, he may also have invoked topographical features behind which the sun disappears.• So this year, to be on the safe side, she had ordered a roll of chicken wire and metal stakes.• I've had a few copies made to be on the safe side: solicitors, banks ... you know.• Most employers, to be on the safe side, would have fired a lot more workers. 