What is the word to describe defining something by what it is not?

Question

Any ideas? Thanks!

Answer 1

The term is APOPHASIS, its adjective form is APOPHATIC

"apophasis" means "denial"
"apophatic" means "negative", or "done by denial"

The terms are most often used to refer to a particular approach to theology -- called "apophatic theology" or the "via negativa" ("negative way/path"), which describes God by saying what he is NOT. (The opposite, positive method is "cataphatic")
http://en.wikipedia.org/wiki/Negative_theology
http://www.rssupport.org.uk/u6/u6phil/vian.html
http://quicksitemaker.com/members/prayer/CT123.html

But it can be used more broadly to refer to
"a method of logical reasoning or argument by denial, a way of telling what something is by telling what it is not, a process-of-elimination way of talking about something by
talking about what it isn't"

An example of this sort of "apophatic inquiry" is found in the guessing game "Twenty Questions".

More on this method -
http://en.wikipedia.org/wiki/Apophasis

See also:
http://dictionary.reference.com/browse/apophatic
http://dictionary.reference.com/browse/apophasis

Answer 2

a million. Experimental 2. desperate 3. satisfied/bright ^_^ 4. stupid (the stable sort! i like to act like a baby and shaggy dog tale around) 5. Smartish (academically) 6. coastline, rain or shine 7. Horseback driving 8. Twilight and vampires 9. communicate approximately desires in sleep 10. Loves holiday upload: Y'understand what, although? i could could desire to locate someplace to slot in chocolate...I dunno the place, yet in simple terms theory i could throw that available, lol

Answer 3

Do you mean an oxymoron?

A Fine Mess
A just war
A little big
a little pregnant
A new classic
absolutely unsure
abundant poverty

Answer 4

Definition by exclusion.

Answer 5

one literary term is "litotes."
"The weather isn't bad." or "This quiche isn't overbaked."
Iitotes is often a tool of sarcasm, as in, "She doesn't waste any time dressing well."

Answer 6

lack of...