u·ni·ty

[yoo-ni-tee]

–noun, plural -ties. 

1. the state of being one; oneness.

2.a whole or totality as combining all its parts into one.

3.the state or fact of being united or combined into one, as of the parts of a whole; unification.

4.absence of diversity; unvaried or uniform character.

5.oneness of mind, feeling, etc., as among a number of persons; concord, harmony, or agreement.

6.Mathematics .     a. the number one; a quantity regarded as one.     b. identity (def. 9) .

7.(in literature and art) a relation of all the parts or elements of a work constituting a harmonious whole and producing a single general effect.

8.one of the three principles of dramatic structure (the three unities)  derived from Aristotelian aesthetics and formalized in the neoclassic canon in which a play is required to represent action as taking place in one day (unity of time),  as occurring within one place (unity of place),  and as having a single plot with a beginning, middle, and end (unity of action).