Clitty litter is what ends up in the crotch of a woman's panties. It consists of dried semen, vaginal secretions, and any other material the woman may be shedding from her uterine and vaginal lining. It can also consist of bits of toilet paper, and if the woman is very unclean, bits of fecal matter, also known as shit. A dingleberry may detach from the hair around the woman's anus, and this too may end up becoming clitty litter.
Clitty litter can be white, red, green, or even brown. This depends on the recent activity of the woman, and her attention to personal hygiene. Check the woman's panties for skid marks!
I was going to go down on that bitch, but that good-looking pussy smelled of ass. Being sneaky, I checked her panties, and found the vented cotton panel to be soaked with dried clitty litter. I then directed me to give me a blow job.
Example two: My girlfriend just got out of the shower, so there was little chance of encountering any nasty clitty litter.