noun
tautology
taw-TOL-uh-jee
Tautology (noun) means the needless repetition of an idea in different words, such as "free gift" or "a new innovation". Example: “Return back" is a tautology; "return" already contains the idea of going back.”
noun
1
The needless repetition of an idea in different words, such as "free gift" or "a new innovation".
""Return back" is a tautology; "return" already contains the idea of going back."
"The report was padded out with tautologies to reach the word count."
2
technical In logic, a statement that is true in every possible case because of its structure alone, such as "either it will rain or it will not rain".
"A tautology carries no information, since it rules nothing out."
How to use tautology
Learner’s notesIn plain EnglishSaying the same thing twice in different words for no reason.
When to use it
The rhetorical sense is common in editing and style guides; the logical sense is technical.
Memory tip
The adjective is tautological (or tautologous), and it is usually a criticism.
Trace the full origin ↓
Easily confused with
Common pairings
mere tautology
avoid tautology
logical tautology
a tautology of terms
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Fill the gap
Can you complete this real example?
"Return back" is a _____; "return" already contains the idea of going back.
Etymology
From Greek tautologia, from tauto "the same" and logos "word, saying".
Synonyms
View more →Antonyms
Related words
Rhymes for tautology
See all rhymes for tautology →Frequently asked questions
What is the difference between a tautology and a pleonasm?
A pleonasm uses more words than necessary — "with my own eyes". A tautology repeats the same idea in a different form — "a free gift". In everyday criticism the two are often used interchangeably, and many pleonasms are also tautologies.
What is the difference between a tautology and a paradox?
A tautology is always true and tells you nothing; a paradox appears self-contradictory yet may reveal something true. They sit at opposite ends of informativeness.
Are tautologies always wrong?
No. In writing they are usually a fault to be edited out, but in logic and mathematics a tautology is a valid and useful thing — every logically valid argument form is one. Some tautologies also survive as fixed idioms, like "ATM machine".
What is the meaning of tautology?
"tautology" (noun) means the needless repetition of an idea in different words, such as "free gift" or "a new innovation".
