su·mo 
(smō)
(smō)n.
A Japanese form of wrestling in which a competitor loses if forced from the ring or if any part of his body except the soles of his feet touches the ground.
[Japanese sumō : su, mutually + mō, to rush at.]
sumoAsashoryu (right) and Hakuho (left), both of Mongolia, at the July 2007 Grand Sumo Tournament
Nagoya, Japan