Barb/bɑːrb/ Definition 1 of 3Pro Tip 1/3Physical Object A barb is often part of a tool or object, like a fishhook, wire, or plant. The rose's thorns had sharp barbs. Pro Tip 2/3Caution Advised 'Barb' conveys potential danger, reminding to handle with care. Wear gloves to avoid the barbs on the wire. Pro Tip 3/3Trap or Hold Barbs are designed to trap or hold onto things, difficult to remove. The bur's barbs stuck to my sweater, making it hard to pull off.