PART (noun)

1. A portion, division, piece, or segment of a whole.
2. Any of several equal portions or fractions that can constitute a whole or into which a whole can be divided: a mixture of two parts flour to one part sugar.
3. A division of a literary work: a novel in three parts
4. (used with a pl. v.)
a. An organ, member, or other division of an organism: A tail is not a part of a guinea pig.
5. A component that can be separated from or attached to a system; a detachable piece: spare parts for cars.
6. A role: He has the main part in the play.
7. One's responsibility, duty, or obligation; share: We each do our part to keep the house clean.
8. Individual endowment or ability; talent. Often used in the plural.
9. A region, area, land, or territory. Often used in the plural: "Minding your own business is second nature in these parts"
10. The line where the hair on the head is parted.
11. Music
a. The music or score for a particular instrument, as in an orchestra.
b. One of the melodic divisions or voices of a contrapuntal composition.