tautology

noun

1. 1

   Redundant use of words, a pleonasm, an unnecessary and tedious repetition.

   “It is tautology to say, "Forward Planning".”

2. 2

   An expression that features tautology.

3. 3

   In propositional logic: a statement that is true for all truth values of its propositional variables. In first-order logic: a statement that is true for all truth values of its Boolean atoms.