aa

a-a · noun

imported

Definitions

noun

  1. 1.

    A type of rough, jagged lava with a broken, clinkery surface, formed when viscous molten lava flows slowly and its surface cools and fragments.

  2. 2.

    (Abbreviation) Alcoholics Anonymous, a support organization for people recovering from alcoholism.

Forms

plural: aas

Phrases & expressions

  • •
    aa lava — The rough, clinkery type of volcanic rock (as opposed to smooth pahoehoe).

Related words

Antonyms: pahoehoe
See also: lava, pahoehoe, volcanic
Synonyms: lava rock

Etymology

From Hawaiian ʻaʻā, referring to this type of lava. The word is onomatopoeic, reportedly imitating the sound one makes when walking barefoot on the sharp rocks.