Madarchod is an abusive word in Hindi slang, a common insult and profanity in the Hindi language and is widely considered obscene and inappropriate.
An abuser usually says Madarchod when he/she is frustrated and is so angry that he/she teases the abusee that he/she fucks his/her (abusee's) own mother.
Its variations are MakiChud, MakaChud, MakaBhosda, MadarChot which simply means the vagina of the abusee's mother.
These are called variations simply because they are originated from Madarchod although they have different meaning.
Another very common abusive word in Hindi slang, Bahanchod, has the same meaning except with the difference that in this case it is not the mother but the sister. Bahanchod is more widely used than Madarchod.