From Wikipedia:
In rhetoric, a tautology is an unnecessary or unessential (and sometimes unintentional) repetition of meaning, using different and dissimilar words that effectively say the same thing twice (often originally from different languages). It is often regarded 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.
Previous WOTD – Charticle

There are two very funny things about that comic. First, it’s amazing just how quickly Tautology Facebook groups popped up after that comic was posted. Second, it’s really funny how many people joined those groups that don’t grasp what tautology is at all. Half of the comments were great examples of tautology. The other half were statements containing two opposite statements (e.g., the tautology club will grow, or it won’t).
Below is a great example from today’s news:
U.S. herpes rates remain high: *1 in 6 Americans infected with herpes
http://www.reuters.com/article/idUSN0923528620100309
“Douglas said the increased rate of infection in blacks is not do to increased risk behavior but likely due to biological factors that make women more susceptible as well as the higher rate of infection within black communities.”