adj. & n.
--adj.
1. Biol. of, relating to, or exhibiting commensalism.
2 (of a person) eating at the same table as another.
--n.
1. Biol. a commensal organism.
2 one who eats at the same table as another.
Derivatives:
commensality n.
Etymology: ME f. F commensal or med.L commensalis (in sense 2) (as COM-, mensa table)