I just read a post where someone was using the adjective splendiferous and even remarked he would not use that word lightly.
So I did a quick search and found that it has the same meaning as splendid, as well as the same function, i.e. both are adjectives.
What is special about splendiferous in contrast to splendid?
From the Online Etymology Dictionary:
considered a playful elaboration since its re-birth in 1843, but it was a perfectly good 15c. word, from Medieval Latin splendorifer, from splendor (see splendor) + ferre “to bear” (see infer).
Thus, it’s a valid word with approximately the same meaning and usage as splendid, but it’s now considered more fanciful than the simpler word, more appropriate for whimsical or ostentatious contexts.