TAUTOLOGY

tautology

(noun) useless repetition; “to say that something is ‘adequate enough’ is a tautology”

tautology

(noun) (logic) a statement that is necessarily true; “the statement ‘he is brave or he is not brave’ is a tautology”

Source: WordNet® 3.1

Etymology

Noun

tautology (countable and uncountable, plural tautologies)

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

(countable) An expression that features tautology.

(countable, logic) 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.

Antonyms

• (linguistics: expression): contradiction in terms

• (in logic): contradiction

• (literary): oxymoron

Coordinate terms

• (in logic): contingency, contradiction

Source: Wiktionary

Tau*tol"o*gy, n. Etym: [L. tautologia, Gr. tautologie.] (Rhet.)

Definition: A repetition of the same meaning in different words; needless repetition of an idea in different words or phrases; a representation of anything as the cause, condition, or consequence of itself, as in the following lines: -- The dawn is overcast, the morning lowers, And heavily in clouds brings on the day. Addison.

Syn.

– Repetition.

– Tautology, Repetition. There may be frequent repetitions (as in legal instruments) which are warranted either by necessity or convenience; but tautology is always a fault, being a sameness of expression which adds nothing to the sense or the sound.

Source: Webster’s Unabridged Dictionary 1913 Edition