- light in weight.
- being lighter in weight, texture, etc., than another item or object of identical use, quality, or function: a lightweight topcoat; a lightweight alloy for ship construction.
- without seriousness of purpose; trivial or trifling: lightweight reading.
- of or relating to a lightweight: He’s the new lightweight contender.
- (of a horse, especially a hunter) able to carry up to 165 pounds (75 kg).
- a person of less than average weight.
- Informal. a person who is of little influence, importance, or effect.
- a boxer or other contestant intermediate in weight between a featherweight and a welterweight, especially a professional boxer weighing between 126 and 135 pounds (56.7–61 kg).
- of a relatively light weight
- not serious; trivial
- a person or animal of a relatively light weight
- a professional boxer weighing 130–135 pounds (59–61 kg)
- an amateur boxer weighing 57–60 kg (126–132 pounds)
- (as modifier)the lightweight contender
- a wrestler in a similar weight category (usually 115–126 pounds (52–57 kg))
- informal a person of little importance or influence
adj.also light-weight, 1773 in horse-racing, also in pugilism; from light (adj.1) + weight. Figurative sense of “inconsequential” first attested 1809.