welterweight (Noun) — A weight of 28 pounds; sometimes imposed as a handicap in a horse race (such as a steeplechase).
welterweight (Noun) — An amateur boxer who weighs no more than 148 pounds.
welterweight (Noun) — A wrestler who weighs 154-172 pounds.
welterweight (Noun) — A professional boxer who weighs between 141 and 147 pounds.