A statement that is true by definition or that restates the same thing in different words — saying the same thing twice, dressed differently.
From Greek tautologia (repetition of what has been said), from tauto (the same) + logos (word). In logic, a tautology is always true (P or not-P). In rhetoric, it is a flaw — unnecessary repetition that says nothing new.
In logic, a tautology is always true. In language, it is always empty. "It is what it is" is a tautology — technically irrefutable, practically meaningless. The word exposes a sneaky trick: sounding wise by saying nothing.
Complete word intelligence in one call. Free tier — 50 lookups/day.