To burst a testicle in a nasty crash. Coined by Jer Wyatt after pro Welsh downhill mountain biker Steve Jones blew out a testicle when competing in the World Cup last year. Example: Did you hear? Jonesy popped a cod in the States last week.
POP A COD
Meaning of POP A COD in English
Slang English vocab. Английский сленговый словарь. 2012