n (card games) A playing card showing a single pip, typically the highest or lowest ranking card in a game.
n (dice games) A die face marked with a single dot, typically representing the number one.
n The ball marked with the number 1 in pool and related games.
n (US, slang) A dollar bill.
n A very small quantity or degree; a particle; an atom; a jot.
n (tennis, volleyball) A serve won without the opponent hitting the ball.
n (sports) A point won by a single stroke, as in handball, rackets, etc.
n (US, baseball) The best pitcher on the team.
n (US, baseball, dated, 19th century) A run.
n (US, golf, disc golf) A hole in one.
n (sometimes attributive) An expert at something; a maverick, genius; a person of supreme talent.
n A military aircraft pilot who is credited with shooting down many enemy aircraft, typically five or more.
n (US) A perfect score on a school exam.
n Any of various hesperiid butterflies.
n (physics, obsolete) A quark.
v (transitive, US, informal) To pass (a test, interviews etc.) perfectly.
v (transitive, intransitive, US, informal) To defeat (others) in a contest; to outdo (others) in a competition.
v (transitive, intransitive, tennis) To win a point against (an opponent) by an ace.
v (golf) To make an ace (hole in one).
adj (UK, slang) Excellent.
adj (slang) Asexual, not experiencing sexual attraction.
n (slang) A person who is asexual.
n A male given name.
n A common nickname suggesting skill, particularly among airplane pilots.
n (file format) A proprietary data compression archive file format.
n (film) A member of American Cinema Editors
n (US, education) Initialism of American Council on Education.
n (astronautics) Initialism of Advanced Composition Explorer, a NASA spacecraft.
n Initialism of American Cinema Editors.
n Initialism of Attempto Controlled English. [A subset of English with restricted syntax and semantics described by a small set of formal rules, suitable for knowledge representation and specification or as a query language.]
n (biochemistry, medicine) Initialism of angiotensin converting enzyme. [(biochemistry) An enzyme which catalyzes the creation of angiotensin, and is a strong vasoconstrictor.]
n (military, NATO) Initialism of air combat element.
n (military, USMC) Initialism of aviation combat element.
n Initialism of analysis and control element.
n (computing) Initialism of arbitrary code execution.
n (computing) Initialism of access control entry.
n (computing) Initialism of ASCII-compatible encoding.
n (psychology) Initialism of adverse childhood experience.
n (meteorology) Initialism of accumulated cyclone energy.