The Collaborative International Dictionary of English v.0.48:

AAAS \AAAS\ n.
   1. the American Association for the Advancement of Science,
      an organization with headquarters in Washington, D.C. Its
      goal is to advance the physical and social sciences, and
      it publishes a weekly journal Science, with original
      research articles as well as reviews and commentary.
      [Acronym.]

   Syn: American Association for the Advancement of Science.
        [WordNet 1.5]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

AAAS
       American Association for the Advancement of Science (org., USA)