The prefix "un-" means "not," making the meaning of uninhibited "not inhibited, not restrained or holding back." Someone who is uninhibited is not afraid to act however he or she wishes.
Uninhibited is the opposite of inhibited, from the Latin inhibēre, "to prohibit or hinder." In the late 19th century the word took on a new importance to psychologists, describing a person not afraid to express emotions, even in public. The following quote from writer Norman Podhoretz gives a contextual definition: "Creativity represents a miraculous coming together of the uninhibited energy of the child with its apparent opposite and enemy, the sense of order imposed on the disciplined adult intelligence."