Noun

• S: (n) feeder, tributary, confluent, affluent (a branch that flows into the main stream)
• direct hypernym / inherited hypernym / sister term
• S: (n) branch (a stream or river connected to a larger one)
• S: (n) stream, watercourse (a natural body of running water flowing on or under the earth)
• S: (n) body of water, water (the part of the earth's surface covered with water (such as a river or lake or ocean)) "they invaded our territorial waters"; "they were sitting by the water's edge"
• S: (n) thing (a separate and self-contained entity)
• S: (n) physical entity (an entity that has physical existence)
• S: (n) entity (that which is perceived or known or inferred to have its own distinct existence (living or nonliving))
• derivationally related form
• antonym

Adjective

• S: (adj) tributary ((of a stream) flowing into a larger stream)
• S: (adj) tributary (paying tribute) "a tributary colony"
• similar to
• S: (adj) obligated (caused by law or conscience to follow a certain course) "felt obligated to repay the kindness"; "was obligated to pay off the student loan"
• antonym
• W: (adj) unobligated [Indirect via obligated] (not obligated)
• S: (adj) conducive, contributing, contributive, contributory, tributary (tending to bring about; being partly responsible for) "working conditions are not conducive to productivity"; "the seaport was a contributing factor in the growth of the city"; "a contributory factor"