or a'a

[ ah-ah ]
/ ˈɑ ɑ /


basaltic lava having a rough surface.

Words nearby aa

Compare pahoehoe.

Origin of aa

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

Definition for aas (2 of 3)


Fellow of the American Academy.

Origin of A.A.S.

From the New Latin word Academiae Americanae Socius

Definition for aas (3 of 3)


American Academy of Sciences.
Associate in Applied Science.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for aas

British Dictionary definitions for aas (1 of 3)

/ (ˈɑːɑː) /


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

Word Origin for aa


British Dictionary definitions for aas (2 of 3)


abbreviation for

ana 1

British Dictionary definitions for aas (3 of 3)


abbreviation for

Alcoholics Anonymous
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

Medicine definitions for aas



Alcoholics Anonymous
amino acid
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for aas

[ ää ]

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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.