Sentence:  During the 30-minute <WSD>gatecrash</WSD>, Mr Lee and his groomsmen did challenges such as forming a human pyramid and dancing to pop tunes such as Britney Spears' Toxic. 
Meaning of the word marked with <WSD> tags:  Part of a traditional Chinese wedding ceremony in which the groom and his groomsmen complete several difficult or embarrassing tasks prepared by the bridesmaids to prove his love for the bride.