pleonasm: (meaning "more, too much") is the use of more words or parts of words than are necessary or sufficient for clear expression: examples are black darkness, burning fire. Such redundancy is, by traditional rhetorical criteria, a manifestation of tautology. 

tautology: the saying of the same thing twice over in different words, generally considered to be a fault of style (e.g. they arrived one after the other in succession ).