Is there a standard dictionary for referencing English words? I am working on a paper in which we need to reference the meaning of english words as foundation for the analysis in the paper (we are categorizing situations using these words, and there is no method of categorizing these items, so no precedent). 

Before internet, using the encyclopedia Britannica or merriam-webster dictionary was easy for referencing the book itself.  These days, words and meanings change and are sometimes updated.  Even more, looking online for a dictionary for finding a word returns many results.  

When searching for oxford dictionary there are three results
http://www.oxforddictionaries.com/
http://www.oed.com/
http://oaadonline.oxfordlearnersdictionaries.com/

Merriam webster:
http://www.merriam-webster.com/

Cambridge:
http://dictionary.cambridge.org/

The online dictionary:
http://www.thefreedictionary.com/

And of course wikipedia usually has some definition.

For example, if we categorize something as 'multi-' , In this dictionary: http://oaadonline.oxfordlearnersdictionaries.com/dictionary/multi multi is "More than one".  However, in this http://www.merriam-webster.com/dictionary/multi , multi is "More than two".  That is a huge difference in terminology.

Is there an academic standard for the age of online dictionaries?  Have words just begun to mean different things and its futile to use dictionaries in this way?
www.oed.com is the online version of the full, official Oxford English Dictionary. Requires a subscription (institutional or personal) to access. This is the site you should use whenever possible.
http://www.oxforddictionaries.com is an ad-supported version with some features cut. Avoid if you have subscription access to the full site (as any university should).
http://oaadonline.oxfordlearnersdictionaries.com/ is, clearly, for learners of the English language. Use it as a guide for learning, sure - but not as a guide for writing papers.


The OED is the English dictionary to use. Other dictionaries are probably fine in all but the weirdest corner cases, but it helps to have some standardization.

Your journal probably specifies its own preferences in this regard. Every publisher's "guide for authors" that I have seen tells you to defer to the OED. Sometimes you'll see specific instructions to use either British or American spellings, and you may specifically be told how to spell words that don't have a British or American "standard" spelling, such as parametrize.