Synergy

n. combined action of two or more agents which produces a result stronger than their individual efforts; cooperation between two or more groups, combined action

Synergy (from the Greek synergos, συνεργός meaning working together, circa 1660) refers to the phenomenon in which two or more discrete influences or agents acting together create an effect greater than that predicted by knowing only the separate effects of the individual agents. It is originally a scientific term. Often (but not always, see Toxicologic synergy, below) the prediction is the sum of the effects each is able to create independently. The opposite of synergy is antagonism, the phenomenon where two agents in combination have an overall effect which is less than that predicted from their individual effects. Synergism stems from the 1657 theological doctrine that humans will cooperate with the Divine Grace in regeneration[1]. The term began to be used in the broader, non-theological, sense by 1925. Synergy can also mean:A mutually advantageous conjunction where the whole is greater than the sum of the parts.A dynamic state in which combined action is favored over the sum of individual component actions. Behavior of whole systems unpredicted by the behavior of their parts taken separately. More accurately known as emergent behavior[1]
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Noun
1. the working together of two things (muscles or drugs for example) to produce an effect greater than the sum of their individual effects
(synonym) synergism
(hypernym) natural process, natural action, action, activity
(hyponym) potentiation

(n.)
the combined healthy action of every organ of a particular system; as, the digestive synergy.
  

(n.)
Combined action
  

(n.)
An effect of the interaction of the actions of two agents such that the result of the combined action is greater than expected as a simple additive combination of the two agents acting separately. Also synergism.
  

see Marketing Synergy.