Gast transitive verb [ Middle English gasten , g...sten to frighten, akin to Goth. usgaisjan . See Aghast , Ghastly , and confer Gaze .] To make aghast; to frighten; to terrify. See Aghast . [ Obsolete] Chaucer. Shak. Found on http://www.encyclo.co.uk/webster/G/12