add. ·noun one of less than average weight;.
2. lightweight ·add. ·noun a person of small impotance or mental ability.
3. lightweight ·add. ·adj light in weight, as a coin; specif., applied to a man or animal who is a lightweight.
4. lightweight ·add. ·noun in boxing, wrestling, ·etc., one weighingnot more than 133 pounds (u. s. amateur rules 135 pounds, ·eng. 140 pounds).