An organism whose presence within another is interpreted as parasitic but which is only present by accident; (formerly also) †a hemiparasite, an organism apparently but not strictly parasitic, such as an epiphyte or saprophyte (obsolete).
Origin
Late 19th century.
Definition of pseudoparasite in US English:
pseudoparasite
noun
Biology
An organism whose presence within another is interpreted as parasitic but which is only present by accident; (formerly also) †a hemiparasite, an organism apparently but not strictly parasitic, such as an epiphyte or saprophyte (obsolete).