to make fun of someone by their apperance, orientation,race, etc or to make it easier to joke on someone
"aye hitlers mama has one big titty and one small titty and they named the bitch biggie smalls"
"nigga if ya keep siggin on mah mama then nigga ill shoot yah!"
To put your head between your knees, and make a gutteral noise with your throat while holding your ankles and attempting to hop in a circle.
Joe sat down and started sigging because his head hurt.