What is Yardmouth?
1. An extremely vulgar insult
2. Used to describe one who enjoys the eating of grass, mulch, dirt, and other objects commonly found in yards
See also: Spacemouth, Mountainmouth, Rotundamouth et al.
Ugh...Drew...you're such a yardmouth!
Hey, look at that yardmouth eating his grass and dirt...haha...yardmouth.