"Ravenous" is already a complete word meaning extremely hungry.
However, you could use a suffix to modify the intensity of the word:
* -ly: Ravenously (adverb)
* -ness: Ravenousness (noun)
You could also add a prefix for a different shade of meaning:
* Un-: Unravenous (not hungry at all)
Ultimately, the best choice will depend on the specific context and desired meaning.