The Collaborative International Dictionary of English v.0.48:

Shriek \Shriek\, v. i. [imp. & p. p. Shrieked; p. pr. & vb. n.
   Shrieking.] [OE. shriken, originallythe same word as E.
   screech. See Screech, and cf. Screak.]
   To utter a loud, sharp, shrill sound or cry, as do some birds
   and beasts; to scream, as in a sudden fright, in horror or
   anguish.
   [1913 Webster]

         It was the owl that shrieked.            --Shak.
   [1913 Webster]

         At this she shrieked aloud; the mournful train
         Echoed her grief.                        --Dryden.
   [1913 Webster]

WordNet (r) 3.0 (2006):

shrieking
    n 1: sharp piercing cry; "her screaming attracted the neighbors"
         [syn: scream, screaming, shriek, shrieking,
         screech, screeching]
    2: a high-pitched noise resembling a human cry; "he ducked at
       the screechings of shells"; "he heard the scream of the
       brakes" [syn: screech, screeching, shriek, shrieking,
       scream, screaming]

Moby Thesaurus II by Grady Ward, 1.0:

37 Moby Thesaurus words for "shrieking":
   acute, argute, blinding, creaky, crude, ear-piercing, flaring,
   flashy, flaunting, garish, gaudy, glaring, howling, keen, keening,
   loud, lurid, overbright, penetrating, piercing, piping, raw, reedy,
   screaky, screaming, screeching, screechy, sharp, shrieky, shrill,
   squeaking, squeaky, thin, ululant, wailing, whining, whistling