Definition of "AO"
AO
/eɪ ˈəʊ/
proper noun
(tennis) Abbreviation of Australian Open, a major tennis tournament, part of the Grand Slam
(video games) Initialism of Anarchy Online.
noun
plural AOs
(US, Navy) Abbreviation of auxiliary oiler.
(quantum mechanics, physical chemistry) Initialism of atomic orbital.
adjective
not comparable