COLLABORATION
collaboration, coaction
(noun) act of working jointly; “they worked either in collaboration or independently”
collaboration, collaborationism, quislingism
(noun) act of cooperating traitorously with an enemy that is occupying your country
Source: WordNet® 3.1
Etymology
Noun
collaboration (countable and uncountable, plural collaborations)
(uncountable) The act of collaborating.
(countable) A production or creation made by collaborating.
(uncountable) Treasonous cooperation.
Source: Wiktionary
Col*lab`o*ra"tion, n.
Definition: The act ofworking together; united labor.
Source: Webster’s Unabridged Dictionary 1913 Edition