Webster's Revised Unabridged Dictionary · 1913

Galligaskins

Galligaskins , noun, plural

[Probably corrupted from Italian Grechesco Grecian, a name which seems to have been given in Venice, and to have been afterwards confused with Gascony, as if they came from Gascony.]

Loose hose or breeches; leather leg guards. The word is used loosely and often in a jocose sense.