Sentence:  <WSD>Sitzfleisch</WSD>: a term used in chess to indicate winning by use of the glutei muscles--the habit of remaining stolid in one's seat hour by hour, making moves that are sound but uninspired, until one's opponent blunders through boredom. 
Meaning of the word marked with <WSD> tags:  The ability to endure or carry on with an activity.