spoken or performed without practicing or preparing

unrehearsed, improvised

not natural or real; made by humans

fake; imitation

(to make) (something) made or done in imitation of another thing in order to deceive

fake, simulated

without preparation

unrehearsed, improvised

not real or genuine; to make fun of (a person, way of speaking etc) (especially by copying in an unkind or disrespectful way)

artificial, fake

false; not genuine

counterfeit, fake

not authentic

counterfeit, fake