adj. having the nature of or relating to a tautology, or a statement which is necessarily true; "Tautologous statements can never be falsified."

adj. repetition of same sense in different words; "`a true fact' and `a free gift' are pleonastic expressions"; "the phrase `a beginner who has just started' is tautological"; "at the risk of being redundant I return to my original proposition"- J.B.Conant