aa
or a'a
[ ah-ah ]
/ ˈɑ ɑ /
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noun
basaltic lava having a rough surface.
QUIZ
THINGAMABOB OR THINGUMMY: CAN YOU DISTINGUISH BETWEEN THE US AND UK TERMS IN THIS QUIZ?
Do you know the difference between everyday US and UK terminology? Test yourself with this quiz on words that differ across the Atlantic.
Question 1 of 7
In the UK, COTTON CANDY is more commonly known as…
Compare pahoehoe.
Origin of aa
First recorded in 1855–60, aa is from the Hawaiian word ʿaʿā
Other definitions for aa (2 of 7)
Origin of a̅a̅
From the Greek word aná, with superscript bar representing the nasal consonant
Other definitions for aa (3 of 7)
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)
Other definitions for aa (6 of 7)
Other definitions for aa (7 of 7)
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use aa in a sentence
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)
AA
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
Scientific definitions for aa
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.
The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.