Noun

(en noun)

(pejorative) A person who lives on other people's efforts or expense and gives little or nothing back.

(biology) an organism that lives on or in another organism, deriving benefit from living on or in that other organism, while not contributing towards that other organism sufficiently to cover the cost to that other organism.

* {{quote-magazine, date=2013-03

, author= , title=The Smallest Cell , volume=101, issue=2, page=83 , magazine= citation , passage=It is likely that the long evolutionary trajectory of Mycoplasma went from a reductive autotroph to oxidative heterotroph to a cell-wall–defective degenerate parasite . This evolutionary trajectory assumes the simplicity to complexity route of biogenesis, a point of view that is not universally accepted.}}

''Lice, fleas, ticks and mites are widely spread parasites .

(literary, poetic) A climbing plant which is supported by a wall, trellis etc.

* 1813 , (Percy Bysshe Shelley), Queen Mab , I:

Her golden tresses shade / The bosom’s stainless pride, / Curling like tendrils of the parasite / Around a marble column.

Noun

(en noun)

A recipient of hospitality, specifically someone staying by invitation at the house of another.

*

, title=(The Celebrity), chapter=5 , passage=We expressed our readiness, and in ten minutes were in the station wagon, rolling rapidly down the long drive, for it was then after nine. We passed on the way the van of the guests from Asquith.}}

A patron or customer in a hotel etc.

An invited visitor or performer to an institution or to a broadcast.