Refers to a biological parasite that lives on or inside a host organism. Also used figuratively for a person who lives off others.
Cats can sometimes have parasites.
He lives off his parents like a parasite.
The test revealed that he had parasites in his stomach.
You can become infected with parasites from eating raw fish.
We removed the parasites from the dog's body.
He's living as a parasite off his parents without working.