The phrase "invincible season" means a sports team's successful season where they do not lose any matches or games. They are unbeatable throughout the entire season. Full definition
Simple really, because in my opinion the two biggest reasons for Arsenal not having won it since the amazing invincibles season of 2004 is our ever present injury crisis and the pressure of expectation and what it does to us. (justarsenal.com)
Next season we need new players and a change of tactics but above all a consistency we have never had since the invincibles (justarsenal.com)
Chief executive Ivan Gazidis heaped praise on Wenger for his incredible 22 - year service which delivered three titles, seven FA Cups and that amazing Invincibles season in 2003/2004. (thesun.ie)