What is "brobdingnag"

(not *brobdignag), 1727, Swift's name in "Gulliver's Travels" for imaginary country where everything was on a gigantic scale.

Brobdingnag is a fictional land in Jonathan Swift's satirical novel Gulliver's Travels occupied by giants. Lemuel Gulliver visits the land after the ship on which he is travelling is blown off course and he is separated from a party exploring the unknown land. Apparently this name is a typo, as in the book prologue Gulliver calls it Brobdingrag.

The adjective Brobdingnagian has come to describe anything of colossal size.