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15.
STM
STM is slang for smiling to myself and is very similar to abbreviations like LOL (laugh out loud) and FTW (For The Win)It is one of the fastest growingly used words and next year will be added in the English dictionary.

Oh, and it is often mistaken for STI or STD (sexually transmitted infection/disease)
Nat.: Oh, remember that time with that teddy bear
Jess: Haha! STM :)
by berackk July 26, 2011
 
16.
STM
refering to the graffiti clique "Stop The Madness".orginating form the BAY AREA!!
Dude1:hey,look at that cool tag
Dude2:yup,STM did that
by JESUSLIVES!!!!!! March 26, 2009
 
17.
Sick to my Stomach
ohhh STMS :(
by Guru^garzaH May 28, 2010
 
18.
STM
1. "SHUT THE MOUTH"

2. A kind, quick response to a text from a girlfriend.

3. When you really mean STFUB.
AutoText Entry:"STM"

GF txt: "Get a job"
BF txt: "STM"
by Cpl Caveman November 06, 2009
 
19.
STM
1. "SHUT THE MOUTH"

2. A kind, quick response to a text from a girlfriend.

3. When you really mean STFUB.
AutoText Entry:"STM"

GF txt: "Get a job"
BF txt: "STM"
by Cpl Caveman November 06, 2009
 
20.
STM
Acronym for "spanking the monkey".
I gotta go on cam to STM before the wife gets back.
by livva_nyc February 27, 2009
 
21.
STM
Short for Stab that Mutherfuker

John says "he's a dickhead ay"
Ned Says "fuk yea STM"
John Says 'Haha yeah"
by JL Sikkent March 08, 2009