Tautology

Tautology was the unnecessary repetition of words that effectively meant the same thing. The Sixth Doctor explained that "Galapagos" meant tortoise, and so the Galapagos tortoise was really the "tortoise tortoise." (AUDIO: Bloodtide)

Luke Rattigan was irritated by people who used tautology, particularly when the Tenth Doctor called his invention the "ATMOS system" when ATMOS already stood for "Atmospheric Omission System". This would be the equivalent of saying "Atmospheric Omission System system". (TV: The Sontaran Stratagem)

The Fourth Doctor found the GlobeSphere company name a bit tautological, (AUDIO: Energy of the Daleks) while the Eighth Doctor later thought of the phrase "tidal wave" as pointlessly tautological since all waves are tidal. (AUDIO: The Next Life)