Noun. The vaginal discharge of blood produced by the uterus on a montly basis during a woman's reproductve years; menstrual blood (Army usage, circa 1985)
I wanted to fuck her, but she was on the rag and I didn't want to get my cock covered with groin gravy.
The clear sauce you put on a pussy au jus open-faced sandwich.
Growling at all the herbivores, he rose from the feast, not bothering to wipe the groin gravy from his mouth.