A neologism is a newly coined word, which just means a made-up word that might or might not catch on.
methodography: In Harry Shearer's Le Show, a fictional pollster explained allegations of systematic errors in polling data, "So far we're pretty satisfied with the methodology we used. We're looking right now at the deeper layer, the methodography, and by the end of next week we'll have completed an unprecedented methodostomy. Then I think we'll have a much better idea of what we're looking at, or for."
Harry Shearer: Le Show
Urban Dictionary: pietrisycamollaviadelrechiotemexity, a neologism.
Numbers - Words for numbers; the language of numbers, where the neologism, pietrisycamollaviadelrechiotemexity, is used.
Modern words - neologisms for modern times
New words - new joke definitions for existing words
Back-formation (removal of supposed prefixes or suffixes) is one way to coin new words.