—n. 1. a piece of cloth, plastic, or paper that covers the chest and is often tied under the chin of a child to protect the clothing while the child is eating.
2. any similar cloth or part of a garment.
3. the front part of an apron, overalls, or similar protective garment above the waist.
4. Fencing.a piece of canvas attached to the base of the mask, for protecting the throat.
6. put or stick one's bib in,Australian Informal.to interfere.