fantastic vs terrific

fantastic and terrific both are adjectives.

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

As adjectives, fantastic and terrific are synonyms defined as:

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

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

fantastic (adjective)	terrific (adjective)
extraordinarily good or great; used especially as intensifiers	causing extreme terror
extravagantly fanciful in design, construction, appearance	extraordinarily good or great; used especially as intensifiers
ludicrously odd	very great or intense
existing in fancy only
fanciful and unrealistic; foolish