From Longman Dictionary of Contemporary Englishtruismtru‧is‧m /ˈtruːɪzəm/ noun [countable] TRUEa statement that is clearly true, so that there is no need to say it His speech was just a collection of clichés and truisms.
Examples from the Corpus
truism• In purely technical terms, this is all but a truism.• The amendment states but a truism that all is retained which has not been surrendered.• Feminism's death in the 1980s is a truism which I doubt.• It is a truism that you get what you pay for.• That's my first truism about truth.• Amy did think it important to write down the old truism regarding the day of the week a baby is born.• This song of himself is filled with exclamation points and pat truisms, however. 