Wrestling was a sport in which two competitors entered a ring, typically bounded by ropes, where they tried to overpower each other bare-handed.
The Second Doctor once was forced to participate in an inter-species wrestling match, which involved him competing against a giant ape-like creature named Grok, and a single Cyberman. (TVC: The Champion)
According to the Tenth Doctor it was also one of the original Olympic sports practised by the Greeks. (DW: Fear Her)
