'Truism' definitions:

Definition of 'truism'

From: WordNet
noun
An obvious truth

Definition of 'Truism'

From: GCIDE
  • Truism \Tru"ism\, n. [From True.] An undoubted or self-evident truth; a statement which is pliantly true; a proposition needing no proof or argument; -- opposed to falsism. [1913 Webster]
  • Trifling truisms clothed in great, swelling words. --J. P. Smith. [1913 Webster]

Synonyms of 'truism'

From: Moby Thesaurus