Think of it like saying "Spanish" or "French" – it's the name of a language, not a word with a specific English translation.
However, if you are interested in the origin of the word "Malayalam", it comes from the words:
* Malayā (meaning "mountain")
* ālam (meaning "country" or "world")
So, literally translated, Malayalam would mean "the country of the mountains". This reflects the geographical landscape of Kerala, which is bordered by the Western Ghats mountain range.