arm wrestling

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A form of wrestling in which two opponents sit facing each other with usually right hands interlocked and elbows firmly planted, as on a table surface, and attempt to force each other's arm down.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A strength sport with two participants. Each participant grips the other's hand and tries to pin the other's arm onto a surface.