The term 'Pound Denizen' refers to an animal that is found in a pound, which is a facility for the temporary housing of stray or abandoned animals. The two crossword solutions for this term are 'DOG' (3 letters) and 'MUTT' (4 letters). A DOG is a domesticated canine species, while a MUTT is a mixed-breed DOG with no specific pedigree. Both terms can be used to refer to a pound denizen, as these animals are often found in pounds.