To back out of a pre-planned event, especially after weeks/months of dramatic build up to said event. To quit. To wimp out at the last possible minute before being forced to fulfill your duties.
Tito out is derived from Tito Ortiz in Season 11 of The Ultimate Fighter when he, at the last minute, decided he was too "injured" to fight Chuck Liddell.
ayon kay Cadaver Chick ika-16 ng Hunyo, 2010