1. Professional boxers in a weight class with a maximum weight limit of 135 pounds (61 kg)
The lightweight boxing champion defended his title last night.
O campeão de boxe dos pesos leves defendeu seu título ontem à noite.
2. People or things that are not serious, important, or substantial; individuals lacking in ability, influence, or importance
They dismissed the new employees as lightweights in the industry.
Eles descartaram os novos funcionários como pesos leves na indústria.