Champ bit is a term that refers to a horse's bit that has been used extensively and has become soft in the horse's mouth. Synonyms for champ bit include "soft bit," "mouthing bit," "comfort bit," and "gentle bit." A soft bit is one that has been broken in and conforms to the horse's mouth. A mouthing bit is used for young horses in training, to help them get used to the bit and learn to accept it without resistance. A comfort bit is designed with the horse's comfort in mind and is used for horses with sensitive mouths. A gentle bit is similarly designed to be gentle on the horse's mouth and is often used for older horses with worn teeth.