1570, from
Middle English gruen "feel horror, shudder" (c.1300), possibly from
Middle Dutch gruwen or Middle LatinG. gruwen "shudder with fear" (confer Ger. grausam "cruel"), or from a Scand. source (confer Dan. grusom "cruel," grue "to dread," though others hold that these are Low Ger. loan-words). One of the many Scottish words popularized in England by Scott's novels.