instant - definition of instant by the Free Online Dictionary, Thesaurus and Encyclopedia.
in·stant (ĭn′stənt) n. 1. An almost imperceptible space of time. See Synonyms at moment. 2. A particular or precise time: at the instant of combustion. 3. Abbr. inst. The current month: your letter of the 15th instant. 4. A food or beverage designed for q...