: characterized by, living in, or being a close physical association (as in mutualism or commensalism) between two or more dissimilar organisms
The truffle is a … fungus that forms a symbiotic relationship with its host tree. Robb Walsh
Termites harbor diverse symbiotic gut microorganisms, the majority of which are as yet uncultivable and their interrelationships unclear. Yuichi Hongoh et al.
b
: characterized by or being a close, cooperative, or interdependent relationship
Today, art advisers are as diverse as the clients they help. They often work alone and form intimate, symbiotic relationships with the people they serve. Deborah Gimelson
Sigal's study … illustrates how reporters' constant need for news and how government officials' need for publicity and favorable coverage for their agencies combine into a symbiotic relationship between Washington reporters and officials. Charles R. Wright
Some species of clams … live symbiotically with sulfur-loving bacteria: the bacteria, which live on the clams' gills, get sulfide from the clams, and the clams, in turn, feed on the bacteria. Natural History
The irony is that the Pentagon and the Soviet Defense Ministry prosper symbiotically. Arthur M. Schlesinger, Jr.