Gargantuan is a related term of mountainous.
As adjectives the difference between gargantuan and mountainous
is that gargantuan is (obsolete) of the giant gargantua or his appetite while mountainous is having many mountains; rough (terrain); rocky.
gargantuan
English
Adjective
(
en adjective)
(obsolete) Of the giant Gargantua or his appetite.
Huge; immense; tremendous.
Of a tremendous size, volume, degree, etc.
Synonyms
* colossal
* enormous
* giant
* huge
* humongous, humungous
* immense
* See also
References
* (etymology) Gourd, Pumpkin. See Budge Ref, p 803A; (from 'Rev 12'--Revue Egyptologique publiee sous la direction de MM Brugsch, F Chabas, and Eug. Revillout (vol I-XIV))
mountainous
English
Adjective
(
en adjective)
Having many mountains; rough (terrain); rocky.
Resembling a mountain, especially in size.
(by extension, of a problem or task) Very difficult.
Synonyms
* See also
See also
* (l)