The grundle is the area between the penis and the asshole. This area is the most dark and hairy realm of the human male body. I like to call it pergatory - the area between heaven and hell.
"First I'll suck you're cock and if you're nice, I will pet your grundle"
The part of the body between the skin flute and vegemite valley. In men this part of the body is usually hairy and sweats quite profusely. In some cases the grundle is also known to be the source of many dags (faeces mixed with hair)
Also known as a gooch, the grundle is the (usually smelly) region between a man's scrotum and anus. I don't know ifthe small area between a woman's vagina and anus counts as a grundle.
The entirety of one's package and asshole, to inlcude either to cock, balls, taint, and asshole, or vagina, taint, and asshole. One's grundle often bears the brunt of the day's heat and is most likely sweaty and horrificsmelling.