Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
splendiferous (adj.)
is a word many consider typically American in its ebullience, an exuberant, hyperbolic near-synonym for splendid. Most dictionaries don’t limit its usage at all, although some readers may consider it a trifle overenthusiastic. For an Informal bit of showy sparkle, however, there’s nothing wrong with an occasional splendiferous.
