I've checked some online dictionaries and have not found it in some while it does exist in others and so wonder if it's a word or not and unsure how to be sure about such things? Given a word, how can one be sure it exists? Is there an official online dictionary that can be trusted?

  • 2
    Productive suffixes like -ly always form words when applied according to their rules. That’s why they’re called “productive”. – tchrist Dec 6 '15 at 19:44
  • 2
    It would not be trivial to add all possible words that derive from all possible productive affixes, and it would nonsensical to do so. That would be like adding all possible hyphenated "adjective-noun" combinations. Language is inherently combinatoric in an unbounded fashion. – tchrist Dec 6 '15 at 20:11
  • 2
    Furthermore, it is a grave error of the first degree to think that any dictionary contains all words. None do nor ever can: that is not how language works. Neither does a word's absence from this or that dictionary in any way constitute some sort of ipso facto proof that it is not an actual word, nor even in at least a few cases does a word’s presence there prove that it is one. – tchrist Dec 6 '15 at 20:17
  • 1
    @deadrat That would be an error of the second person, for it is yours not mine. – tchrist Dec 6 '15 at 20:29
  • 2
    There's grammar and there's style. adding '-ly' is mostly legal to add to any (longer) adjective. But, as you've had the idea to ask the question, you probably have the inner feeling as a native speaker that 'mediocrely' is an infelicitous sounding word. I would suggest not using it, and use something else. 'in a mediocre manner' sounds a little better to me. – Mitch Jan 15 '16 at 20:43

No, there's no "official" source of English vocabulary. Generally, you're allowed to form adverbs by adding -ly to adjectives, so your first guess should be that mediocrely meaning "in a mediocre manner" is a word. Then check to see whether people use it like this from Larry McMurtry and the West: An Ambivalent Relationship by Mark Busby:

In high school I did a surprising number of things mediocrely. Among these were baseball, basketball, 4-H work, tennis, track, ready writing, editorial writing, extemporaneous speech, drama, declaiming, trombone playing, and debating.

The google reports almost 40K uses online. Even allowing for instances of debate over whether it's a word, that leaves enough to validate your first guess.

  • How did you find that quote? – wolfdawn Dec 6 '15 at 20:09
  • 1
    It's a wonderful example, isn't it? Contrasting the quantity of activities with the quality of the performance of them. I used the Ngram viewer at books.google.com/ngrams, which allows you to find usages and compare different usages as they appear over time in google books. – deadrat Dec 6 '15 at 20:22
  • This is indeed a fascinating tool. It feels like it would do me good service when this sort of question comes up again especially since the words are there even if they continue to elude any dictionaries' definition. For instance you could find a word like Wolvenwhich is often used in phantasy literature to refer to wolf-like humanoids. Very interesting and many thanks. – wolfdawn Dec 6 '15 at 20:40
  • Also good for checking idiomatic usages. Is it "different from", "different than", or "different that"? – deadrat Dec 6 '15 at 21:21
  • Not sure this is clear, lets say we have a sentence that express A isn't equivalent to B and we want to use one of the three options you listed. How would one apply ngrams to this situation? – wolfdawn Dec 8 '15 at 5:36

The Oxford English Dictionary has an entry for mediocrely since OED Third Edition, June 2001. http://www.oed.com/view/Entry/251632

enter image description here

Not the answer you're looking for? Browse other questions tagged or ask your own question.