A severe, disabling headache, usually affecting only one side of the head, and often accompanied by nausea, vomiting, photophobia and visual disturbances.
A neurological condition characterised by such headaches.
1777 re-spelling (following French) of late 14th century Middle English megrim, from 13th century Old French migraigne, from Vulgar Latin pronunciation of Latin hemicrania ("pain in one half of the head"), from Ancient Greek ἡμικρανία, from ἡμι- + κρανίον (whence also cranium), a calque of Egyptian gs-tp ("headache"), from gs + tp, although the link between the Egyptian magical papyri and the Greek ἡμικρανία could be purely incidental.