noun
or tisha b'ab or tish·ah b'av or tisha b'av |tishə|bäv, -bȯv
Usage: usually capitalized T & Ab or Av
Etymology: Hebrew tish'āh bĕ'ābh ninth of Ab
: a Jewish fast day that is observed on the 9th day of Ab in commemoration of the destruction of the First and Second Temples at Jerusalem — called also Ninth of Ab