For all the fellow word geeks out there...

15 words that are (probably) made up, but commonly used...

1. Administrate: A back-formation of administration and an unnecessary extension of administer



2. Commentate: A back-formation of commentator and an unnecessary extension of comment



3. Dimunition: Erroneous; the correct form is diminution (think of diminutive)



4. Exploitive: A younger, acceptable variant of exploitative



5. Firstly: As with secondly and thirdly, erroneous when enumerating points; use first and so on



6. Heighth: Rarely appears in print, but a frequent error in spoken discourse (Why isn't height modeled on the form of depth, length, and width? Because it doesn't shift in spelling and pronunciation from its associated term, tall, like the others, which are derived from deep, long, and wide, do. Neither do we say or write weighth.)



7. Irregardless: An unnecessary extension of regardless on the analogy of irrespective but ignoring that regardless, though it is not an antonym of regard, already has an antonymic affix



8. Miniscule: A common variant of minuscule, but widely considered erroneous



9. Orientate: A back-formation of orientation and an unnecessary extension of orient



10. Participator: Erroneous; the correct form is participant



11. Preventative: A common and acceptable variant of preventive



12. Societal: A variant of social with a distinct connotation (for example, "social occasion," but "societal trends")



13. Supposably: An erroneous variant of supposedly



14. 'Til: Also rendered til and till, an clipped form of until that is correct but informal English; use the full word except in colloquial usage



15. Undoubtably: An erroneous variant of undoubtedly