/s 

Indicates the presence of sarcasm.

Man, I wish George Bush could take another 4 years, especially after his work on torture- who'd have thought such a fair and moral decision could have been made?

/s

/s by thisshouldbeeasier April 16, 2008

/s 

Known as the sarcasm switch, this is used to indicate that the previous statement was used ironically.

I love murder /s

/s by Cezico April 23, 2020

's 

How the grammatically-challenged make a noun plural.

Look at all these definition's.

's by Ollie the Dog December 28, 2003

s 

s

s

s by KiJoPL December 10, 2022

S 

This weird letter that is always automatically typed in the “Word” Bar when you try to upload a word into the Urban Dictionary...

“S” probably stands for the word Spermatogenesisicalieperiocladicleesötáans. Well, actually, that isn’t a word, but I uploaded it to the Urban Dictionary and no one voted it to be in it yet god damn it, so do it NOOOOOWWWWWW.........

S by SuperiorSteve64 October 6, 2019

s/ 

Originates from the SED and subsequently the Perl construct for a regular expression substitution: s/REGEXP/SUBST/ will replace whatever matches REGEXP with SUBST. Commonly used in chat contexts by people with a Unix background and/or wannabe hax0rs to either correct their own previous typoes, or change the meaning of somebody else's statement.

Many people also tend to drop the final slash, either because they're lazy or because they don't really know where that expression comes from.

A: trance music sucks
B: s/sucks/rules/

s/ by DJMoses May 27, 2009

s'

a contraction for "it is" one step further than "it's"

s'good = it's good
"hey, did you hear Phil's new album? s'good."

s' by smerganf kokcl February 24, 2009