noun 1.imitation or enactment, as of something anticipated or in testing.
2.the act or process of pretending; feigning.
3.an assumption or imitation of a particular appearance or form; counterfeit; sham.
4.Psychiatry. a conscious attempt to feign some mental or physical disorder to escape punishment or to gain a desired objective.
5.the representation of the behavior or characteristics of one system through the use of another system, especially a computer program designed for the purpose.