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.”
an instance of such repetition.
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 of tautology
1570–80; < Late Latintautologia < Greektautología. See tauto-, -logy
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?
logica 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 (def. 3), contingency (def. 5)
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.)).
