needless repetition of an idea, especially in words other than those of the immediate context, without imparting additional force or clearness, as in “widow woman.”.
2.
an instance of such repetition.
3.
Logic.
a compound propositional form all of whose instances are true, as “A or not A.”.
an instance of such a form, as “This candidate will win or will not win.”.
Origin
1570-80; < Late Latintautologia < Greektautología. See tauto-, -logy
When corporations run governments, blaming the governments for the corporations ailments is a bit of a tautology.
It became a kind of tautology that had enormously powerful policy implications, in theory.
It's a tautology designed to evade self-incrimination.
From the beginning, the equidistance result was carelessly interpreted by a tautology, the constant mutation rate.
She added that she is concerned about some of the tautology going on here.
As a matter of tautology, an appearance bond can be breached only by the nonappearance of the defendant.
British Dictionary definitions for tautology
tautology
/tɔːˈtɒlədʒɪ/
noun (pl) -gies
1.
the use of words that merely repeat elements of the meaning already conveyed, as in the sentence Will these supplies be adequate enough? in place of Will these supplies be adequate?
2.
(logic) a statement that is always true, esp a truth-functional expression that takes the value true for all combinations of values of its components, as in either the sun is out or the sun is not outCompare inconsistency (sense 3), contingency (sense 5)
C16: from Late Latin tautologia, from Greek, from tautologos
Word Origin and History for tautology
n.
1570s, from Late Latin tautologia "representation of the same thing," from Greek tautologia, from tautologos "repeating what has been said," from tauto "the same" + -logos "saying," related to legein "to say" (see lecture (n.)).
tautology in Technology
logic A proposition which is always true. Compare: paradox. The Linguistic Smarandache Tautologies, (https://gallup.unm.edu/~smarandache/tautolog.txt). (1999-07-28)