Taken from the funny blog of Jules, here's a conversation between two Malay girls which she overheard.
Upon reading this, my reaction was:
You cannot say that it's an honest mistake: perhaps the two words seemed the same because they both begin with the letter C and they both relate to surgical procedures to the male private parts, but the similarity ends there.
Circumcision is a procedure where they remove part, or all of the foreskin from the penis. Some guys do it for health and hygiene, and for the muslims, it's almost compulsory: also known as Bersunat in Malay: muslim boys have to go through in order to mark themselves a true muslim (Source) I don't know how it exactly works, so if you want to be further educated visually, there is always Youtube.
Castration occurs when you loose function of your testicles, or your balls (popular-speak), or your bolah(in malay). The procedure can also be summarised as "your balls being yanked off", thus disabling you from producing sperm, and of course you wouldn't be able to have children. In cases where a man contracts testicular cancer, he'll have to go through a castration, in order to remove the affected areas. People were castrated back then as a form of punishment back then as well! The Chinese men of ancient China, who became Eunuchs also voluntarily castrate themselves in other to work in the Imperial Service.
What's the correct word to use then?
Contrary to what the Malay Girl mentioned, both procedures does not (necessarily) mean "cut the dick off". For true blue "cutting the dick off", you could use the word Bobbitt instead. The word Bobbitt is popularised from the surname of John Bobbitt, a man who had his penis chopper-chopped off and flung out of a car by his wife (Source).
So, people, please use words that you understand lah please. *FACEPALM*