Top definition
Term to refer to a mans balls after recently being shaved, when the small prickly hairs begin to grow back and poke his penis as it hangs over them.
Guy: Damn, I got the cactus effect. Should've shaved better.
Guy 2: I know, that shit sucks. Feels like tiny needles stabbing your dick.
by PurplePagan May 19, 2007
Get the mug
Get a The cactus effect mug for your buddy Jovana.