gamma-aminobutyric acid gam·ma-a·mi·no·bu·tyr·ic acid (gām'ə-ə-mē'nō-byōō-tēr'ĭk, -ām'ə-nō-) n. Abbr. GABA An amino acid that occurs in the central nervous system and that is associated with transmission of inhibitory nerve impulses.
(gām'ə-ə-mē'nō-by-tîr'ĭk, -ām'ə-) An amino acid occurring in the brain as a neurotransmitter that acts to inhibit the transmission of nerve impulses. Certain antianxiety drugs, called benzodiazepines, mimic the actions of gamma-aminobutyric acid. Chemical formula:C4H9NO2.