Emily Dickinson Lexicon

ME'GRIM, n. [Fr. migraine, corrupted from L. and G. hemicrania, half the head.]

Properly, a neuralgic pain in the side of the head; periodical headache, characterized by a vehement pain confined to one side of the head, sometimes to one side of the forehead, and usually periodical, i.e. either exacerbating and unremitting, or absolutely intermittent.