偏头痛；周期性偏头痛

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.

These are his megrims, firks, and melancholies.
--Ford.

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.


migraine \mi*graine"\, 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.