a person, animal, plant, group, etc., that is part of a society, party, community, taxon, or other body.

Government .

a member of Congress, esp. of the House of Representatives.

a member of the British Parliament, esp. of the House of Commons.

any member of a legislative body.

a part or organ of an animal body; a limb, as a leg, arm, or wing.

Botany . a structural entity of a plant body.

the penis.

a constituent part of any structural or composite whole, as a subordinate architectural feature of a building.

Mathematics .

either side of an equation.

an element of a set.

Geology . a stratigraphic unit recognized within a formation, and mapped as such.

being a member of or having membership in an association, organization, etc.

member countries of the United Nations.

noun

affiliate , associate , branch , chapter , component , comrade , constituent , cut , division , joiner , offshoot , parcel , piece , portion , post , representative , section , segment , unit , arm , element , extremity , feature , fragment , leg , limb , organ , part , subdivision , fellow , plenum , quorum