from
The Collaborative International Dictionary of English v.0.48
Megrim \Me"grim\, n. [OE. migrim, migrene, F. migraine, LL.
hemigrania, L. hemicrania, hemicranium, Gr. ?; ?- half + ?
skull. See {Hemi-} and {Cranium}, and cf. {Hemicrania},
{Migraine}.]
1. A kind of sick or nervous headache, usually periodical and
confined to one side of the head; now more commonly called
{migraine headache} or {migraine}.
[1913 Webster +PJC]
2. A fancy; a whim; a freak; a humor; esp., in the plural,
lowness of spirits.
[1913 Webster]
These are his megrims, firks, and melancholies.
--Ford.
[1913 Webster]
3. pl. (Far.) A sudden vertigo in a horse, succeeded
sometimes by unconsciousness, produced by an excess of
blood in the brain; a mild form of apoplexy. --Youatt.
[1913 Webster]