Tishah b’Av (ti??a b??av) n (Judaism) Judaism the ninth day of the month of Av observed as a fast day in memory of the destruction of the First and Second TemplesCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Tish?ah b’Av or Tish?ah b’Ab (?t?? ? ?b?v, ti??? b???v) n. a Jewish fast day observed on the ninth day of Av in memory of the destruction of the First and Second Temples in Jerusalem. [