1. noun: having a large diameter penis. The white mans answer to the long skinny black penis. The whiteside is usually muscular in appearance and can be compared to a pringles can.
2. adjetive: a slang term most often associated with a penis of large girth; capable of increasing vaginal circumference
see also: pringle can, coke can, stalky stub muscle, Matthew's holy hammer
1. Matthew has a whiteside that is so big it gets locked up in his old lady and the firemen have to spray them apart with a firehose. Because of this, he moved to an apartment closer to the fire hydrant.
2. Matthew has a thick bulge in his pants. He must have a whiteside penis.
A fat middle age man with a beer gut, he makes love with his teenage son secretly and enjoys it more than having sex with his wife. Similar to a Peadophile but the victim (son) doesn't object to to the love sports.
Kid1: Ey dude, did you hear? Micks old man was busted for whiteside!
Kid 2: Yuck. I always thought Mick was a bit wierd.