A tautology refers to a statement or phrase that is repetitive or redundant, saying the same thing twice using different words. It is an unnecessary and often unhelpful repetition that doesn't add any new information. Full definition
Yet the latter are not mere tautologies of the sort that, once you deny the subject you can deny the predicate. (religion-online.org)
Redundancies, also known as tautologies, seem (at least to some) to add a formal, airtight quality to the language. (lawyerist.com)
There are some examples of tautology in sentences: new innovation; personally I; the evening sunset; first priority; in my opinion, I think that; sleepily sleepy; my own; morning sunrise; first and foremost; etc.. (advanced-writer.com)