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 pertaining to a lightweight

He's the new lightweight contender.

(of a horse, esp. a hunter) able to carry up to 165 lb. (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, esp. a professional boxer weighing between 126 and 135 lb. (56.7?61 kg).

adjective

big , consequential , heavyweight , important , major

adjective

failing , featherweight , foolish , imponderous , incompetent , insignificant , of no account , paltry , petty , slight , trifling , trivial , unimportant , weightless , worthless