marvelous vs terrific

marvelous and terrific both are adjectives.

Word	Noun	Adjective	Verb	Adverb
marvelous	No	Yes	No	No
terrific	No	Yes	No	No

As adjectives, marvelous and terrific are synonyms defined as:

marvelous and terrific: extraordinarily good or great; used especially as intensifiers

Other synonyms of marvelous include fantastic, grand, howling, marvellous, phenomenal, rattling, tremendous, wonderful, wondrous.

marvelous (adjective)	terrific (adjective)
extraordinarily good or great; used especially as intensifiers	causing extreme terror
too improbable to admit of belief	extraordinarily good or great; used especially as intensifiers
being or having the character of a miracle	very great or intense