1. In botany, a plant which grows on another plant, but which does not, like a parasite, derive its nourishment from it.

Many orchids and also some ferns and many mosses, liverworts, lichens, and algæ are examples.

2. In zoology, a fungus parasitic on the skin and its appendages or on mucous surfaces of humans and other animals, causing disease; a dermatophyte.