Definition of shrieks:
(v) :
(intransitive) 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.
(n) :
A sharp, shrill outcry or scream; a shrill wild cry caused by sudden or extreme terror, pain, or the like.
(v) :
(transitive) To utter sharply and shrilly; to utter in or with a shriek or shrieks.
(n) :
(UK, slang) An exclamation mark.