the needless repetition of an idea, statement, or word
an instance of this
in logic, a statement that is true by virtue of its logical form; an analytic proposition
tautological /-ʹlojikl/ adj
tautologically /-ʹlojikli/ adv
tautologous /-gəs/ adj
tautologously /-gəsli/ adv
[via late Latin from Greek tautologia, from tautologos repeating what has been said, from tauto- + legein to say]