Same as "you should", though it can be use for any subject (I, he, she, we, it, they). Implies advice or warning. Common in the southern US, this phrase has been shortened down from:

You would be better off if you...
You would be better to ...
You'd be better...
You'd better...
You better...

Sometimes as a threat, a person will mistakingly say "you had better...", but the uncontracted version is "would" not "had".
You better get started on that paper if it's gonna be done by Monday.

You better be in this house when the street lights come on.

You better put them trash cans up on the porch, so's the dogs ain't gettin in 'em.
by Coell March 22, 2006
A clause used to begin a sentence describing an impressive action. Note: The subject is variable. Also note: The conjugation of a “you better” phrase is always in the present tense, regardless of when the action described occurred.
Johnathon: how did u finish that video project on time??

Rom: girl.. i better stay up for three days in a row!! lol
by ETERNIA January 12, 2005
Same as "you should", though it can be use for any subject (I, he, she, we, it, they). Implies advice or warning. Common in the southern US, this phrase has been shortened down from:

You would be better off if you...
You would be better to ...
You'd be better...
You'd better...
You better...

Sometimes as a threat, a person will mistakingly say "you had better...", but the correct uncontracted version is "would" not "had".
You better get started on that paper if it's gonna be done by Monday.

You better be in this house when the street lights come on.

You better put them trash cans up on the porch, so's the dogs ain't gettin in 'em.
by Coell March 16, 2006
Like a threat or warning with the sense of advice, meaning if you don’t do smth there’ll be consequences or you’ll just fuck up
- I’ve got a new haircut.
- That’s fucking hot!
- Now I have to learn how to style it..
- You better!

- I bought a new dress but forgot to take a photo. I’ll take a few for you later.
- You better!
by kudryaaa October 20, 2018
A video popular on YouTube In the video a woman yells at a kid when he makes a flamethrower and the woman yells "YOU BETTER STOP, STOP,BITCH STOP" People mainly use it when some thing cringey is said or done.
Normie: Hey want to trade pokemon cards?
Outsider: You Better stop bitch stop.
by Frostyfade33 September 4, 2017
Meaning exactly what it says, you better hope.

I originally heard it in Florida, Tampa bay area. Most people use the term improperly. Look @ Examples.
Improper:

Guy 1: You're so gay.
Guy 2: You better hope.

Proper:

Guy 1: I got the money I owe you.
Guy 2: You better hope.

Proper+Akward:

Guy 1: Good thing you like women, because us two guys hang out quite a lot.
Guy 2: You better hope I like women.
by UrbanNinjanary April 27, 2010
An imperative phrase used to give praise or approval to another person. Note: The subject is variable.

Syn: work, shwerk

See also: you better
Johnathon: those headshots are fierce… you better work!

**********

Rom: did u hear that john-eric hooked up with one of the bel ami boys? he better work!
by ETERNIA January 12, 2005