aa

Initialism of arctic-alpine.

Adjective abbreviation, alt of

  1. Initialism of arctic-alpine.
  2. Initialism of always afloat.

Origin

Abbreviation.

Adjective abbreviation, alt of

  1. Abbreviation of ana (“of each, equal parts”).

Origin

Contraction.

Noun abbreviation, alt of

  1. Initialism of acetic acid.
  2. Initialism of acting age.
  3. Initialism of alveolar-arterial.
  4. Initialism of aminoacetone.
  5. Initialism of amino acid.
  6. Initialism of approximate absolute.
  7. Initialism of arachidonic acid.
  8. Initialism of armature accelerator.
  9. Initialism of ascending aorta.
  10. Initialism of atomic absorption.
  11. Initialism of author's alteration.
  12. Initialism of average audience.

Noun abbreviation, alt of

  1. Abbreviation of adjectives.
  2. Abbreviation of arteries.

Origin

Compare pp.

Noun geography, geology

  1. A form of lava flow associated with Hawaiian-type volcanoes, consisting of basaltic rock, usually dark-colored with a jagged and loose, clinkery surface. Compare pahoehoe.
    • We...saw ‘pahoihoi’ or solid lava forming, and also ‘aa’ or clinkers. - 1859, R. C. Haskell, American journal of science and arts, series XXVIII:
    • Cooling and solidification frequently takes a different course [...] in lava flows, producing the clinker-like ‘aa’ lava. - 1944, Charles A. Cotton, Volcanoes as landscape forms:
    • Both pahoehoe and aa lava flows are common on the upper slopes of Mauna Loa with a preponderance of aa flows found at the lower elevations. - 1981, Hilo Lava Flood Control: Environmental Impact Statement, page 194:

Origin

Etymology tree Proto-Polynesian *kaha Proto-Polynesian *kakaha Hawaiian ʻaʻābor. English aa Borrowed from Hawaiian ʻaʻā.

Forms

a'a 'a'a 'a'ā a-a a aa a-aa

Pronoun

  1. I.