black ace

noun3

1. •
   A player from a junior league who is called up by an NHL team after their original team's season has ended and kept as a reserve player.

   • We'd have our morning skate and then I would have the black aces stay out, the guys that weren't gonna dress. — 2011
2. •
   (slang) An elite mafia hitman.

   • The big man in the Mafia said: 'Billy, me and the boys are praying for you. We know you're up against the big one this time, the big black ace'. — 1968
3. •
   (euphemistic, no longer used) A woman's sexual favours, or a woman who gives them.

   • Blame her not poor Woman, she loves nothing so well as a black ace. — 1676