Sarging is a term that refers to Pick Up Artists going out with the specific purpose to pick up women.
A Pick Up Artist

Pickup artist

Pickup artist describes a man who considers himself to be skilled, or who tries to be skilled at meeting, attracting, and seducing women.The use of pickup in this context, slang for making a casual acquaintance with a stranger in anticipation of sexual relations, dates from at least the World War,...

 (PUA) will use various techniques to attract women, including openers, demonstrating higher value, etc.

A Pick Up Artist has purpose when Sarging, rather than most Average Frustrated Chumps (AFCs) that are pretending to enjoy themselves in the hope of meeting a woman.

The term is said to come from the name of Ross Jeffries

Ross Jeffries

Ross Jeffries is a former comedy writer and the creator of "Speed Seduction," a set of personal development writings and seminars that draw on Neuro-linguistic Programming and hypnotic techniques...

 cat

Cat

The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...

Sargy.