Ace

1. (noun) A single point or spot on a playing card or die. 2. (noun) A card or die face so marked. 3. (noun) The ball marked with the number 1 in pool and related games. 4. (noun) A very small quantity or degree; a particle; an atom; a jot. 5. (noun) A serve won without the opponent hitting the ball. 6. (noun) A single point won by a stroke, as in handball, rackets, etc. 7. (noun) The best pitcher on the team. 8. (noun) (19th century) A run. 9. (noun) A hole in one. 10. (noun) An expert at something. 11. (noun) A military aircraft pilot who is credited with shooting down many enemy aircraft, typically five or more. 12. (noun) A perfect score on a school exam. 13. (noun) Any of various hesperiid butterflies. 14. (noun) A quark. 15. (verb) (US) To pass (a test, interviews etc.) perfectly. 16. (verb) To win a point by an ace. 17. (verb) To make an ace (hole in one). 18. (adjective) Excellent.