A combination of the words smut and sex. While sex can refer only to the mechanics of the act, the addition of smut into the equation (meaning to make obscene or pornographic) gives it a more vulgar connotation than just sex by itself.
This also applies to smexy. To be sexy is to arouse interest (even unintentionally), but to be smexy is to arouse sexual interest in a pointedly lewd manner.
I found a fic featuring my two favorite characters engaging in hot smex.
The images conjured in my mind by the story were so smexy I got a nosebleed.
by douma September 10, 2005
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Used in fangirl circles as a cooler sounding variant to "sex." Can also mean: hot, sexy, cute, cool.

Other meanings vary on use. Be sure to check context!

Used most often in conjunction with "teh".
He is so smexin.

Itz teh smex!

I so wanna smex him.
by Sephirajo December 11, 2004
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word for sex on chat rooms that wont allow the word 'sex' and will ban you if you say it.
girlfreind- hey babe
boyfreind-hey
girlfreind-wanna have sex?
boyfreind- dont say that they will ban you on zwinky
girlfreind-oh ya wanna have smex?
boyfreind- oooohhh ya!
by gabby531875 January 21, 2009
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Smex is the kind of sex you read or watch when looking at or reading any kind of japanese cartoon. Is also used when read yaoi/yuri. Mostly used when reading yaoi/yuri, actually. "Smexy", a word favored by fangirls/boys everywhere, is used to describe any character he/she would like to throw down and screw their brains out...no matter who the character is really SUPPOSED to be with. For instance:
Rei: Gaara, I love you!!! *attacks* I'm gonna throw you down and screw your brains out!!!!
Gaara: I cannot agree. My secret love is for-
Rei: *glomps him and shuts him up* no, tell me after we fuck. Then I'll write a really smexy fanfic!!
by Reiaku May 3, 2006
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Woah! She's such a S(exy)MEX(ican).
That girl is so smexy.
by Phil T. August 19, 2006
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sex
with a 'm'
which stands for monkey
which led to the development of AIDS

so,
any sex in which you contract AIDS
some years ago:
-dude i just had smex last night
-dude i didn't know u were into bestiality

now:
-i shouldn't have had that smex
-yea, thanks for AIDS

OR
-dude i had smex last night
-dude that sucks, when'd you find out it was smex and not sex?
by HenryL January 6, 2008
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A term used in the US Northeast to define dirty, smelly European sex.
It smells like smex in here; That's the kind of smex you can only see on the Internet!
by Edge January 22, 2005
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