[par-uh-sahyt] 
| 1. | an organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment. |
| 2. | a person who receives support, advantage, or the like, from another or others without giving any useful or proper return, as one who lives on the hospitality of others. |
| 3. | (in ancient Greece) a person who received free meals in return for amusing or impudent conversation, flattering remarks, etc. |
| par·a·site (pār'ə-sīt') n.
[Latin parasītus, a person who lives by amusing the rich, from Greek parasītos, person who eats at someone else's table, parasite : para-, beside; see para-1 + sītos, grain, food.] |
An organism that lives off or in another organism, obtaining nourishment and protection while offering no benefit in return. Human parasites are often harmful to the body and can cause diseases, such as trichinosis.
Note: The term parasite is often applied to a person who takes advantage of other people and fails to offer anything in return.
parasite par·a·site (pār'ə-sīt')
n.
An organism that grows, feeds, and is sheltered on or in a different organism while contributing nothing to the survival of its host.
In conjoined twins, the usually incomplete twin that derives its support from the more nearly normal fetus.