Brobdingnagian vs vast

Brobdingnagian and vast both are adjectives.

Word	Noun	Adjective	Verb	Adverb
Brobdingnagian	No	Yes	No	No
vast	No	Yes	No	No

As adjectives, Brobdingnagian and vast are synonyms defined as:

Brobdingnagian and vast: unusually great in size or amount or degree or especially extent or scope

Other synonyms of Brobdingnagian include huge, immense.

Brobdingnagian (adjective)	vast (adjective)
huge; relating to or characteristic of the imaginary country of Brobdingnag	unusually great in size or amount or degree or especially extent or scope
unusually great in size or amount or degree or especially extent or scope