High Quality Content by WIKIPEDIA articles! In rhetoric, a tautology is an unnecessary or unessential repetition of meaning, using different and dissimilar words that effectively say the same thing twice. It is often regarded or thought of as a fault of style and was defined by Fowler as "saying the same thing twice." It is not apparently necessary or essential for the entire meaning of a phrase to be repeated. If a part of the meaning is repeated in such a way that it appears as unintentional, clumsy, or lacking in dexterity, then it may be described as tautology. On the other hand, a repetition of meaning which improves the style of a piece of speech or writing is not necessarily described as tautology.