vulgar slang A piece of cushioning mounted to the stem or handlebars of a bicycle to protect a male's genitals in the event of a sudden stop or collision. "Nards" is a vulgar slang term for the testicles. Boy, good thing my bike still had a nard guard on it when I crashed, or I might have never had kids!
nard guard
n. a male genital protector. (see also nads, nards.) There was a nard guard attached to the center of the handlebars.