I have no doubt that like linguists and grammarians, etymologists also love to argue.

There is little doubt that the words 'testis/testes' and 'testify' are linked.

'Testify' means 'to swear under oath' and/or 'to bear witness to', as we all know. However, what no-one seems to be 100% certain of is that in Ancient Rome, did 'to testify' mean 'to swear by your testicles'?

It was a long time ago now, but I do remember reading something somewhere that in Ancient Rome, if a man was found to be lying under oath then his testes were cut off as punishment.

Truth? Or amusing misconception? Unless Taffy wipes the dust off his time-traveling machine, I guess we can never be 100% certain.