colossal vs prodigious

colossal and prodigious both are adjectives.

Word	Noun	Adjective	Verb	Adverb
colossal	No	Yes	No	No
prodigious	No	Yes	No	No

As adjectives, colossal and prodigious are synonyms defined as:

colossal and prodigious: so great in size or force or extent as to elicit awe

Other synonyms of colossal include stupendous.

colossal (adjective)	prodigious (adjective)
so great in size or force or extent as to elicit awe	far beyond what is usual in magnitude or degree
	so great in size or force or extent as to elicit awe
	of momentous or ominous significance