This article is from the Crosswords FAQ, by James A. Lundon (jlundon@xstacy.enet.dec.com) with numerous contributions by others.
There is no one definitive dictionary that you must have for setting
or solving crosswords. On the other hand, in some contexts, it helps
to know what dictionary has been used in setting a crossword,
particularly for hard crosswords containing unusual words. For
example, The Listener crossword (now published in The Times) almost
always uses "Chambers English Dictionary", with deviations from that
being noted. On the other hand, in America, Merriam-Websters 10th
Collegiate Dictionary is the standard of the National Puzzlers League
(NPL - a wordplay club which devotes some of its time to crosswords).
In both countries there are many other good dictionaries of usable
size. Two mammoth dictionaries that solvers and setters sometimes
have to resort to are The Oxford English Dictionary and
Merriam-Webster's Third New International Dictionary.
The NPL rank the well known dictionaries in order of preference as
follows:
10C (Merriam-Websters 10th Collegiate Dictionary) is better than NI3
(Webster's Third New International) is better than NI2 (Webster's New
International, 2nd Edition) is better than everything else.
Great slang dictionaries for true word mavens include Partridge's "A
Dictionary of Slang and Unconventional English", "A Dictionary of the
Underworld", and "The Routledge Dictionary of Historical Slang".
Spears's "Slang and Euphemism" is quite good, as is Cassidy's
"Dictionary of American Regional English" though only two of the
three volumes have been published.
 
Continue to: