unity

NOUN:
1.     The state or quality of being one; singleness.
2.     The state or quality of being in accord; harmony. 
3a.    The combination or arrangement of parts into a whole; unification.
3b.    A combination or union thus formed.
4.     Singleness or constancy of purpose or action; continuity: “In an army you need unity of purpose”.
5a.    An ordering of all elements in a work of art or literature so that each contributes to a unified aesthetic effect. 
5b.    The effect thus produced.
6.     One of the three principles of dramatic structure derived by French neoclassicists from Aristotle's Poetics, stating that a drama should have but one plot,
 which should take place in a single day and be confined to a single locale. 
7a.     Mathematics: The number 1. 
7b.    Mathematics: See identity element.