Erin McKean:
One thing that shouldn’t stop you from using an undictionaried word: worrying about whether it’s “real” or (as Wordnik users like to say) “madeupical.” All words (aside from unintentional errors and malapropisms) are words at their birth. All you have to decide is whether the word in question is the right one for the job. Dictionaries don’t measure realness; they serve as rough proxies for the extent of a word’s use.