A short term feeling of having lots of energy, one who is hyper usually does crazy/stupid things and laughs a lot. Often called a "natural high" and is caused by mutliple things: friends, sugar, lack of sleep, night, etc
I was so hyper last night i couldn't stop laughing.
by Magical Mara August 9, 2004
When you cant concentrate on anything and you feel like bouncing off the walls...natural high usually...well...sugar
Omg, when i ate the King Sized snickers bar i got totally hyper and was like WOW!
by Hypergirl December 3, 2003
The first syllable is "high" and the second is "purr", therefore to be hyper is to be like a drugged cat. Yes. Really.
"This definition of hyper on urban dictionary is completely incorrect."
by homo sapien #6,839,217,974 November 4, 2009
Extreme to the point of contrapositional self-reference in the next cultural, mathematical, or metaphysical paradigm
The horseshoe political theory in which an individual moves so far to the right so as to support a national safety net is an example of the hyper phenomenona.

Also, the hyper bola reflects itself in opposition across the x or y nodes.
by sandrashine November 20, 2017
In the furry fandom (and most likely other places with sexual minorities), hyper means to be excessively endowed to the point of ridiculous and unrealistic proportions. This can also be combined or replaced with the muscle fetish to mean unrealistically gigantic muscular proportions.
Furry #1: "Hey did you see the artist who drew that hyper mouse?"
Furry #2 "The one with those really really huge boobs, right?"

Or

Furry #1: "Man, I wish I was hyper muscled..."
Furry #2: "Why? You wouldn't even be able to move with all that beef on you."
Furry #1: "It's just for looks."
by Cid SilverWing May 5, 2008
when you eat a lot of sugar and jump around everywhere yelling four square and raawk and telling your teachers to shut up
shut up! FFOOUURR Squaaaare!
!
by PlayDohMan May 14, 2004