aa solidified lava with a rough jagged surface and sharp angular features
    AA achievement age
    AAA American Automobile Association
    AAA Amateur Athletic Association
    AAAL American Academy of Arts and Letters
    AAAS American Association for the Advancement of Science
    AAD automatic activation device
    AAF Army Air Forces
    AAFC Agriculture and Agri-Food Canada
    AAM air-to-air missile
    aapa elder sister (used by Muslims)
    AAR against all risks
    Aachen a German city famous for Charlemagne palace, his tomb and the place where 31 Holy Roman Emperors were crowned
    Aardvark a nocturnal mammal native to Africa. (“aardvark” means “earth pig” in Afrikaans language)
    Aardwolf a small, insectivorous mammal, native to Africa. (“aardwolf” means “earth wolf” in Afrikaans language)
    Aare River the longest river entirely within Switzerland
    aargh used to express annoyance or disgust at something or somebody
    Aaron according to Bible, Aaron is the elder brother of Moses and traditional founder and head of the Jewish priesthood.
    Aaron Hank a legendary American baseball player. In 1974, he hit home run number 715, breaking Babe Ruth’s record. He retired in 1976 with 755 home runs
    AARP a nonprofit organization founded in 1958 by Ethel Andrus to address the needs of Americans aged 50 and older. Its motto is "Real Possibilities" and its bimonthly magazine, Modern Maturity, has the largest circulation of any American periodical. Its Headquarters is in Washington, D.C.
    Aarti (आरती) a Hindu religious ritual of worship in which light from wicks soaked in ghee (clarified butter) or camphor is offered to one or more deities. Aartis also refer to the songs sung in praise of the deity, when lamps are being offered.
    AAS American Academy of Sciences
    aasvogel South African vulture
    AAU Amateur Athletic Union
    AAUP American Association of University Professors
    AAVE African American Vernacular English