Definition of "Lightweight" :

noun: a professional boxer who weighs between 131 and 135 pounds

noun: a wrestler who weighs 139-154 pounds

noun: an amateur boxer who weighs no more than 132 pounds

noun: someone who is unimportant but cheeky and presumptuous

adjective: weighing relatively little compared with another item or object of similar use

"A lightweight fabric."

adjective: having no importance or influence

"A lightweight intellect."