Gast

• (v. t.) To make aghast; to frighten; to terrify. See Aghast.
Found on http://thinkexist.com/dictionary/meaning/gast/

Gast

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
No exact match found