C18: from Brobdingnag, an imaginary country of giants in Swift's Gulliver's Travels (1726)
Brobdingnagian in American English
(ˌbrɑbdɪŋˈnæɡiən)
adjective
1.
of huge size; gigantic; tremendous
noun
2.
an inhabitant of Brobdingnag
3.
a being of tremendous size; giant
Word origin
[brobdingnag + -ian]-ian is a suffix occurring originally in adjectives borrowed from Latin, formed from nounsdenoting places (Italian) or persons (Flavian), and now productively forming English adjectives by extension of the Latin pattern.Attached to geographical names, it denotes provenance or membership (Washingtonian), the latter sense now extended to membership in social classes, religious denominations,etc. (Episcopalian; pedestrian). Attached to personal names, it has the additional senses “contemporary with” ( Victorian) or “proponent of” (Hegelian; Freudian) the person specified by the noun base. It also occurs in a set of personal nouns,mainly loanwords from French, denoting one who engages in, practices, or works withthe referent of the base noun (comedian; grammarian; theologian)