Bolero/bəˈlerəʊ/ Definition 1 of 3Pro Tip 1/3Fashion Item A bolero is a piece of clothing, not a style or overall look. I need to buy a bolero to wear over my sleeveless dress. Pro Tip 2/3Formal Events Boleros are often worn at formal events to add elegance while offering modest coverage. She chose a silk bolero for the gala. Pro Tip 3/3Mix and Match Boleros can be paired with different outfits, not necessarily only with dresses. He paired his jeans with a casual bolero.