1) expressing approval/enthusiasm
2) expressing that something is a well known fact or that someone has just stated the obvious
"I'm gonna gets me some vodka and smuggle it in"
" you know that shit!!"

"This office party is gonna be so lame"
"you know that" i.e of course

" I wish Rocky B hadnt changed his name to MC Platnum"
"You know that" i.e true that mother fucker its a fucking travesty
by Emily Lan November 9, 2006
1. A Concise phrase, where the context of the matter doesn't need to be explained. Usually said to someone out of the loop/ not up to date/ is not aware.

2. Having knowledge or being aware of something especially through personal experience.

3. Street Smarts

4. Being Cognizant
Person 1:

What was that about?
What were they talking about?
Is that true?
How do you know THAT?
Person 2:

Don't worry about it. If you know, you know.
-
by LinguisticsOfTime March 18, 2020
The defining phrase of an inside joke/access to information only a select few know about
You see your mate's laptop screen saver is a naked girl, but her face is covered , you know who it is, but others don't- you post it on your snapchat and put "....'s screensaver, if you know, you know"
by Resting peace August 29, 2015
A way of agreeing or accepting something said.
Jimbob-"That kid is so salty that you kicked his ass!"
Steveo-"You know, you know..."
by Yeagermeister January 26, 2005
A derogatory prepatory statement in a sentence used when telling someone something they should already know, but, in fact the author knows they do not.
As you know, gang leadership is run from the Prison Infrastructure.
by Marc Habel September 16, 2008
Said in agreement to a statement or question. See word
-Thats a massive spliff you just rolled
-You know it
by Stoner 04231 November 25, 2003
Said by absolute wankers and utter cunts feeling smug and clever
A: says joke
B: scratches head
A: if you know, you know - and doesn't explain. There's a superior undertone, supposedly to manipulate the listener into giving AF. Said usually by completely banal people with nothing to show for their total and self-absorbed mediocrity
by psycheward January 26, 2022