Sudden diminution or loss of consciousness, sensation, and voluntary motion, usually caused by pressure on the brain.
- Sudden impairment of neurological function, especially that resulting from a cerebral hemorrhage; a stroke.
- A sudden effusion of blood into an organ or tissue.
- A fit of extreme anger; rage: "The proud . . . members suffered collective apoplexy, and this year they are out for blood” ( David Finch).