noun
A statement that is true by definition or repeats the same idea in different words; used in logic and rhetoric.
「すべての独身者は結婚していない」はトートロジーの例だ。
"All bachelors are unmarried" is an example of a tautology.
A more formal or academic Japanese term for tautology, while トートロジー is the direct loanword commonly used in logic and everyday contexts.
Borrowed from English 'tautology', ultimately from Greek 'tautologia'.