1. Living in a relationship in which one organism derives food or other benefits from another organism without hurting or helping it. Commensal bacteria are part of the normal flora in the mouth.

"one who eats at the same table" (as another), c. 1400, from Old French commensal (15c.), from Medieval Latin commensalis, from com- "together" (see com-) + mensa (genitive mensali [..]

microorganism (pop)

(L: com= with/together; mensa=table; dining together) a species living in close association with another species. One organism benefits, the other does not, but neither is harmed. For example, the Rem [..]

Populations of house mice that depend upon human-built habitats or food production for survival. 

(n) either of two different animal or plant species living in close association but not interdependent(adj) living in a state of commensalism

Having benefit for one member of a two-species association but neither positive nor negative effect on the other

a relationship in which two or more organisms (e.g., humans and mice) live in close association and in which one may derive benefit from the other, and neither harms the other

Living on or within another organism and benefiting without harming or benefiting the host.

The term commensalism refers to a type of relationship between two different organisms that “eat from the same dish”. In this kind of relationship, neither benefits from the other or provokes any harm. It is therefore a neutral relationship. Other classes of relationships between organisms include mutualism, in which both organisms obtain benefits, [..]

 Healthy or “good” bacteria that live in an animal’s body e.g. in the intestines.

A two-species association in which there is a positive effect on one species and neither a positive nor a negative effect on the other.

A usually harmless microorganism, but one which may cause illness in an immunocompromised person