know better

present singular third person knows better · participle present knowing better · past knew better · participle past known better

1. set phraseTo recognize that a statement or belief is false or doubtful.

   "Kapoor Brothers told us they had no books or records, but we knew better and were able to search and find them."

   1987 April 24, Bruce Lambert, “Operator of Newsstands Guilty in Sales Tax Case”, in New York Times, retrieved 19 May 2015

   1 more example

   'Do you think, sir,' said Mr Willet, […] 'do you think, sir, that I'm a born fool?' 'No, no, Johnny,' returned Solomon, looking round upon the little circle of which he formed a part: 'We all know better than that.'

   1841 February–November, Charles Dickens, “Barnaby Rudge. Chapter 54.”, in Master Humphrey’s Clock, volume III, London: Chapman & Hall, […], →OCLC

2. set phraseTo understand that certain behavior is wrongful, futile, or inappropriate.

   "All that happened when he was eight; he's older now and knows better."

   1919, H. H. Munro, “Hyacinth”, in The Toys of Peace and Other Papers

   1 more example

   [B]oth sides know better than to expect that U.S. special envoy Senator George Mitchell's shuttling between Jerusalem and Ramallah will be able to bridge the chasm between their demands.

   2010 March 8, Tony Karon, “Israelis and Palestinians: Agreeing to Talk, and to Fail”, in Time, retrieved 19 May 2015

   Synonyms: know any better