Initialism of above Ordnance Datum. Used to specify heights above mean sea level on General Arrangement and other technical drawings. Usually specified in metres, eg +62.0m.

(rare) Macau (especially in China's English-language media).

(aeronautical) Initialism of angle of attack. / (astronautics) Initialism of abort once around. / (military) Initialism of add-on armor.

Initialism of Administration on Aging.

(economy) Initialism of all or nothing, a type of stock market or financial derivative order, signifying that the order is to be executed only if the full quantity of the order can be bought or sold.

Any other business. / Away on break.

(grammar) Of, or relating to the aorist aspect.

(grammar) A grammatical category of verbs that expresses perfective aspect (also known as aorist aspect) and past tense. The nearest equivalent in English is the simple past.

(grammar) Of or pertaining to a verb in the aorist aspect.

(military, UK) Initialism of Air Officer Commanding, a title used to refer to RAF officers holding certain command appointments. / Initialism of age of consent. / Initialism of author of color.