Sentence:  Harkening back to the days when loggers had to break river jams free by carefully stepping out on floating logs, <WSD>logrolling</WSD> is all about maintaining balance. Also called birling, <WSD>logrolling</WSD> requires competitors to go head-to-head on a single log, trying to toss the other guy into the water by forcing him to lose his balance. 
Meaning of the word marked with <WSD> tags:  A sport in which two people balance on a log floating in a body of water, each one aiming to cause the opponent to fall off by rolling or kicking the log.