Blow out Definition 1 of 5Pro Tip 1/2Celebratory Action Often associated with celebrations, especially birthdays, where blowing out candles is a tradition. After making a wish, she blew out the candles. Pro Tip 2/2Use Caution Be careful not to spit on food like birthday cakes while blowing out candles. Remember to blow out gently, so you don't ruin the cake.