n. [ F. migraine, LL. hemigrania, L. hemicrania, hemicranium, Gr. "hmikrani`a; "hmi- half + krani`on skull. See Hemi- and Cranium, and cf. Hemicrania, Migraine. ] 1. A kind of intense sick or nervous headache, usually periodical and confined to one side of the head; called also migraine headache. Same as megrim. -- Mi*grain"ous, a. [1913 Webster]