lad

a Jack the Lad (British, informal, old-fashioned)

a confident and not very serious young man who behaves as he wants to without thinking about other people. Three children with three different women? Well, he always was a bit of a Jack the Lad.

See also: jack

one of the lads (British & Australian, informal, American, informal)

someone who is accepted as part of a group of male friends who all have similar ideas and interests. Greene, although not one of the lads, is popular with most of them.