aa

or a'a

[ ah-ah ]

/ ˈɑ ɑ /

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noun

basaltic lava having a rough surface.

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Compare pahoehoe.

Origin of aa

First recorded in 1855–60, aa is from the Hawaiian word ʿaʿā

Other definitions for aa (2 of 7)

a̅a̅

or āa

Symbol.

(in prescriptions) ana².

Origin of a̅a̅

From the Greek word aná, with superscript bar representing the nasal consonant

Other definitions for aa (3 of 7)

AA¹

abbreviation

administrative assistant.

Other definitions for aa (4 of 7)

AA²

Symbol.

a proportional shoe width size, narrower than A and wider than AAA.

the smallest proportional brassiere cup size.

a quality rating for a corporate or municipal bond, lower than AAA and higher than A.

Electricity. a battery size for 1.5-volt dry cells: diameter, 0.6 inch (1.4 centimeters); length, 2 inches (5 centimeters).

British. a designation for motion pictures certified as unsuitable for children under 14 unless accompanied by an adult.Compare A³ (def. 10), U⁵ (def. 6), X³ (def. 9).

Other definitions for aa (5 of 7)

a.a.

or aa

abbreviation

author's alteration. Also A.A., AA

Other definitions for aa (6 of 7)

A.A.¹

or AA

[ ey-ey ]

/ ˈeɪˈeɪ /

abbreviation, noun

Alcoholics Anonymous.

Other definitions for aa (7 of 7)

A.A.²

abbreviation

antiaircraft.Also AA

Associate in Accounting.

Associate of Arts.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use aa in a sentence

ROME — What does it take for a Hollywood A-lister to get a private audience with Pope Francis?
Pope Francis Has the Pleasure of Meeting Angelina Jolie for a Few Seconds|Barbie Latza Nadeau|January 8, 2015|DAILY BEAST
Yes, Byrd—dead four-and-a-half years now—was a Kleagle in the Ku Klux Klan.
Steve Scalise and the Right’s Ridiculous Racial Blame Game|Michael Tomasky|January 2, 2015|DAILY BEAST
By the time it concluded with a sing-a-long of “XO,” Beyoncé had done the rare thing.
Bow Down, Bitches: How Beyoncé Turned an Elevator Brawl Into a Perfect Year|Kevin Fallon|December 31, 2014|DAILY BEAST
In another year, stories about the strange new face of an A-list actress might draw chortles and cackles.
Renée Zellweger Got a New Face—and Everyone Had An Opinion About It|Kevin O’Keeffe|December 29, 2014|DAILY BEAST

Because Duck Dynasty receives monster TV ratings and Robertson paid by a company (A&E) while making these public statements.
Butts, Brawls, and Bill Cosby: The Biggest Celebrity Scandals of 2014 |Kevin Fallon|December 27, 2014|DAILY BEAST
Now-a-days it is the bankrupt who flouts, and his too confiding creditors who are jeered and laughed at.
Glances at Europe|Horace Greeley
He felt himself the meanest, vilest thing a-crawl upon this sinful earth, and she—dear God!
St. Martin's Summer|Rafael Sabatini
All that scientific bric-a-brac in the cupboard had far better be thrown away.
The Salvaging Of Civilisation|H. G. (Herbert George) Wells
Urinary sediments may be studied under three heads: A. Unorganized sediments.
A Manual of Clinical Diagnosis|James Campbell Todd
I knowed, a-course, that I could go kick up a fuss when Simpson stopped by his office on his trip back from Goldstone.
Alec Lloyd, Cowpuncher|Eleanor Gates

British Dictionary definitions for aa (1 of 3)

aa¹

/ (ˈɑːɑː) /

noun

a volcanic rock consisting of angular blocks of lava with a very rough surface

Word Origin for aa

Hawaiian

British Dictionary definitions for aa (2 of 3)

aa²

abbreviation for

ana 1

British Dictionary definitions for aa (3 of 3)

abbreviation for

Alcoholics Anonymous

anti-aircraft

Architectural Association

(in Britain) Automobile Association

(in Britain) Advertising Association

symbol for

(in Britain, formerly) a film that may not be shown publicly to a child under fourteen

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for aa

abbr.

Alcoholics Anonymous

amino acid

aminoacyl

Scientific definitions for aa

[ ä′ä ]

A type of lava having a rough, jagged surface. It is relatively slow moving in its molten state, advancing in the form of massive blocks with fissured and angular surfaces that ride on a viscous interior. The blocks range in size between the size of a football and the size of a house. See Note at pahoehoe.

aa

or a'a

Origin of aa

Other definitions for aa (2 of 7)

or āa

Origin of a̅a̅

Other definitions for aa (3 of 7)

Other definitions for aa (4 of 7)

Other definitions for aa (5 of 7)

or aa

Other definitions for aa (6 of 7)

or AA

Other definitions for aa (7 of 7)

Words related to aa

How to use aa in a sentence

British Dictionary definitions for aa (1 of 3)

Word Origin for aa

British Dictionary definitions for aa (2 of 3)

British Dictionary definitions for aa (3 of 3)

Medical definitions for aa

Scientific definitions for aa