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.