means To utter a sharp, high-pitched cry or sound, usually from fear, pain, or excitement.

from From Middle English 'schriken,' likely of imitative origin — a word built to mimic the very noise it names. It's a close cousin of 'screech' and 'screak,' and probably entered English with a Scandinavian flavor (compare Old Norse 'skrækja,' to screech). The whole little family — shriek, screech, scream — sounds like what it means, the language flinching at its own pitch.