1) small pieces of rubbish that have been left lying on the ground in public places
2) a group of animals that are born at the same time and have the same mother
3) dried grass or plant stems used by animals as a bed
4) a substance that is put in a container to be used as a toilet by pets
1) to spread across an area or place untidily
Well, yes, but where is the pun?Kitty litter can mean 'a batch of cat babies', the stuff cats urinate and defecate into if they are kept inside, or that someone is littering (throwing out bits of garbage) with kitty chunks. It's sounds kind of disturbing said like that though.
Definition of pun
the usually humorous use of a word in such a way as to suggest two or more of its meanings or the meaning of another word similar in sound