bad boy

noun4

1. •
   A man whose rebellious nature makes him dangerous or attractive.

   • Yeah, I fit the profile all right. Perfect made-to-order malcontent. Let's sign this bad boy up and sic him on somebody fast, before the foam dries on his mouth. — 2012
2. •
   (slang) A powerful or impressive product or item.

   • Many school music teachers and directors are not primarily clarinetists and, knowing little of the subtle intricacies of this "bad boy" of instruments, can teach little more than the fingering. — 1949
3. •
   (slang) A male criminal.
4. •
   (slang, figurative) An undesirable or difficult task.

   • Let's get this bad boy done!