Merriam-Webster Collegiate Dictionary - unity

 noun  (plural -ties)  Etymology: Middle English unite, from Anglo-French unite, from Latin unitat-, unitas, from unus one — more at one  Date: 14th century  1.  a. the quality or state of not being multiple ; oneness  b.  (1) a definite amount taken as one or for which 1 is made to stand in calculation in a table of natural sines the radius of the circle is regarded as ~  (2) identity element  2.  a. a condition of harmony ; accord  b. continuity without deviation or change (as in purpose or action)  3.  a. the quality or state of being made one ; unification  b. a combination or ordering of parts in a literary or artistic production that constitutes a whole or promotes an undivided total effect; also the resulting singleness of effect or symmetry and consistency of style and character  4. a totality of related parts ; an entity that is a complex or systematic whole  5. any of three principles of dramatic structure derived by French classicists from Aristotle's Poetics and requiring a play to have a single action represented as occurring in one place and within one day  6. capitalized a 20th century American religious movement that emphasizes spiritual sources of health and prosperity