无：没有；
与：和
伦：类
伦比：类比,匹敌.
指事物非常完美,没有能与它相比的.
后来也用来形容才艺超群,无人能敌.
“无与伦比”在汉英词典中的解释(来源：百度词典)：
1.incomparable; unrivaled; unequalled; peerless; unique; matchless; unparalleled
2.to defy all comparison; to be beyond (or past) compare; to be without comparison; to be without rival; to be beyond challenge; to be without (a) parallel
例句
罗格宣布北京奥运会闭幕(2008年08月24日) 称其“真正的无与伦比”.9时许,国际奥委会主席罗格宣布,北京奥运会闭幕.在致辞中,罗格称北京奥运会“是一届真正的无与伦比的奥运会”.The Beijing Olympic Games are "truly exceptional Games," said International Olympic Committee (IOC) President Jacques Rogge at the Games' closing ceremony staged in the National Stadium in northern Beijing on Sunday night.