Source : Webster's Revised Unabridged Dictionary (1913)

Eldritch \El"dritch\, a.
   Hideous; ghastly; as, an eldritch shriek or laugh. [Local,
   Eng.]

Source : WordNet®

eldritch
     adj : suggesting the operation of supernatural influences; "an
           eldritch screech"; "the three weird sisters";
           "stumps...had uncanny shapes as of monstrous
           creatures"- John Galsworthy; "an unearthly light"; "he
           could hear the unearthly scream of some curlew piercing
           the din"- Henry Kingsley [syn: {weird}, {uncanny}, {unearthly}]