mem·ber / ˈmembər/ • n. 1. an individual belonging to a group such as a society or team: a member of the drama club interest from members of the public. ∎ an animal or plant belonging to a taxonomic group: a member of the lily family. ∎ (also Member) a person formally elected to take part in the proceedings of certain organizations: members of Congress Member of Parliament. ∎ a part or branch of a political body: [as adj.] member countries of the Central African Customs Union. 2. a constituent piece of a complex structure: the main member that joins the front and rear axles. ∎ a part of a sentence, equation, group of figures, mathematical set, etc.3. archaic a part or organ of the body, esp. a limb. ∎ (also male member) the penis. Compare with membrum virile. ∎ Bot. any part of a plant viewed with regard to its form and position, rather than to its function.DERIVATIVES: mem·bered adj. [in comb.] ( chiefly Chem. ) a six-membered oxygen-containing ring.