A loud, emphatic, exclamation of extreme emotion, especially horror, fear, excitement, or anger; it may comprise a word or a sustained, high-pitched vowel sound.

A loud vocalisation of many animals, especially in response to pain or fear.

(music) A form of singing associated with the metal and screamo styles of music. It is a loud, rough, distorted version of the voice; rather than the normal voice of the singer.

(informal) Used as an intensifier.

(printers' slang) An exclamation mark.

(intransitive, also figurative) To cry out with a shrill voice; to utter a sudden, shout outcry, or shrill, loud cry, as in fright or extreme pain; to screech, to shriek.

(intransitive, figurative) To emit a loud, high-pitched sound, often indicating fear, pain, or excitement.