Tau*tol"o*gy (?), n. [L. tautologia, Gr. &?;: cf. F. tautologie.] (Rhet.) 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.

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.

Tau*tol"o*gy (?), n. [L. tautologia, Gr. &?;: cf. F. tautologie.] (Rhet.) 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.

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.

• (linguistics) (uncountable) Redundant use of words, such as in "a big large fish".
  
• (linguistics) An expression that features tautology.
  
• (logic) A statement that is true for all values of its variables.