bad boy bad boy /bæd bɔɪ/

noun

1. [Informal] A rebellious man who does not conform to usual standards or behavior  ( bad boy [Informal] )
   a rebellious man who does not conform to usual standards or behavior
    Self-described bad boy of Wall Street stands trial
   self-described bad boy of Wall Street stands trial
   
2. [Informal, American] Something impressive or powerful (esp. a car or motorbike)  ( bad boy [Informal, American] )
   something impressive or powerful (esp. a car or motorbike)
    Can't wait to take this bad boy for a spin
   can't wait to take this bad boy for a spin