In the internet age, Latin script is used to write Malayalam (aka Manglish). English can't render all the phonemes of Malayalam, so letters are pronounced differently according to context. "enna" can be both എന്നാ and എണ്ണ.
There are christian prayer books written in Manglish !
@amithm7 Yeah, it might not be. But the term Abba would have solidified the usage of Appa here.
Or maybe Tamil got the word Appa from Syriac too ? or vice-versa.