Sentence:  Sure, you'll get trapped once in a while with a <WSD>flash crowd</WSD>. Like the first time Satchel Paige pitched in Cleveland. We thought we'd get 55,000, and we ended up with 78,000. 
Meaning of the word marked with <WSD> tags:  A large audience for a sporting event that is unexpected because of large numbers of game-day ticket sales rather than advance tickets.