The term 'GYM UNIT' can be represented by the crossword solutions REP, which stands for Representative. A Representative is a person who acts on behalf of another person or organization, typically by speaking, campaigning, or negotiating on their behalf. Representatives are often elected to represent a certain group of people in a government or other organization. In the context of a gym unit, a Representative would be someone who is responsible for representing the interests of the gym and its members.