Logopoeia (a coined word meaning 'word-coining') is a natural activity of English-language speakers; this paragraph, in fact, contains three words in addition to logopoeia that are probably not in any dictionary. But the word-coiner, if not being deliberately nonsensical, is constrained by the desire to get a message across. The practice is more suspect in logology, where the only acknowledged constraint may be the logological goal. Here it is easy to slip from coining words to coining 'words' and thence to words?.
Cohen, Philip M.
Word Ways: Vol. 11
, Article 5.
Available at: http://digitalcommons.butler.edu/wordways/vol11/iss4/5