unity

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The state or quality of being one or united into a whole.
• noun The state or quality of being in accord; harmony.
• noun The state or quality of being unified in an aesthetic whole, as in a work of literature.
• noun A whole that is a combination of parts.
• noun Singleness or constancy of purpose or action; continuity.
• noun 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.
• noun The number 1.

from The Century Dictionary.

• noun The state or property of being one; oneness, as opposed to multiplicity; individuality, as opposed to plurality.
• noun Organic totality; that interconnection of parts which constitutes a complex whole; a systematic whole as distinguished from its constituent parts: as, the unity of consciousness; the unity of an artistic creation. See def. 9.
• noun Identity; self-sameness; uniformity.
• noun The state of being united or combined in one; especially, union as connected parts of a complex whole: as, the national unity of the separate states.
• noun Harmony or accord in sentiments, affection, action, etc.; concord.
• noun Sameness of character or effect; agreement; coincidence.
• noun In mathematics, a quantity which, multiplied by any quantity of the system considered, gives that same quantity as the product.
• noun The principle by which a uniform tenor of story and propriety of representation is preserved in literary compositions; conformity in a composition to this principle; a reference to some one purpose or leading idea, or to the main proposition, in all the parts of a discourse or composition. The so-called Aristotelian law of unity of time, of place, and of action (called ‘the unities’) in a drama was the fundamental rule or general idea from which the French classical dramatic writers and critics derived, or to which they referred, all their practical rules for the construction of a drama. This law demanded that there should be no shifting of the scene from place to place, that the whole series of events should be such as might occur within the space of a single day, and that nothing should be admitted irrelevant to the development of the single plot.
• noun In artistic creations, a combination of parts such as to constitute a whole or to exhibit a form of symmetry in style and character; the quality of any work by which all the parts are subordinate to or promotive of one general design or effect.
• noun In law: The holding of the same estate in undivided shares by two or more; joint tenancy.
• noun The joint possession by one person of two rights by several titles.
• noun A gold coin of the reign of James I. See unite.
• noun See primitive.

from the GNU version of the Collaborative International Dictionary of English.

• noun The state of being one; oneness.
• noun Concord; harmony; conjunction; agreement; uniformity
• noun (Math.) Any definite quantity, or aggregate of quantities or magnitudes taken as one, or for which 1 is made to stand in calculation; thus, in a table of natural sines, the radius of the circle is regarded as unity.
• noun (Poetry & Rhet.) In dramatic composition, one of the principles by which a uniform tenor of story and propriety of representation are preserved; conformity in a composition to these; in oratory, discourse, etc., the due subordination and reference of every part to the development of the leading idea or the eastablishment of the main proposition.
• noun (Fine Arts & Mus.) Such a combination of parts as to constitute a whole, or a kind of symmetry of style and character.
• noun (Law) The peculiar characteristics of an estate held by several in joint tenancy.
• noun at one.
• noun (Biol.) See under Type.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun uncountable Oneness; the state or fact of being one undivided entity.
• noun A single undivided thing, seen as complete in itself.
• noun drama Any of the three classical rules of drama (unity of action, unity of place, and unity of time).`
• noun mathematics Any element of a set or field that behaves under a given operation as the number 1 behaves under multiplication.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the smallest whole number or a numeral representing this number
• noun the quality of being united into one
• noun an undivided or unbroken completeness or totality with nothing wanting