look up any word, like cleveland steamer:
 
1.
Literally, sexual dexterity. Sexterity can be gained through sexual experience(s), or in some cases, pharmaceuticals.
"Man, getting with Nadine gave me mad sexterity!"

or;

"That Viagra really gave me the sexterity to go all night."
by Justin Herbert April 10, 2009
 
2.
The level of sexual skill and ability one has. Can be increased over time with experience or stat enhancing clothing.
Dude, check out my awesome wizard hat. It gives me +7 sexterity.
by The Chubububu October 11, 2009
 
3.
Your sexy ability. Can change depending on attitude, appearance, disposition, location.
Dude! Look at this new shirt. It easily adds 5 to my sexterity.
by Zanderif September 13, 2007