Operating Thetan

According to What is Scientology?, an Operating Thetan is a state involving "knowing and willing cause over life, thought, matter, energy, space and time." At this point, the transition from Clear to OT, Scientology purportedly shifts focus from the mundane to the spiritual, from daily life to eternity.

OT is sometimes used as an adjective suggesting something is very good, powerful, and positive, as in "Owen Starkey, a very OT speaker from the Freewinds ..."

Links

OT Levels described in Understanding Scientology by Margery Wakefield

Operating Thetan - from Scientology at Wikipedia