combustibleness vs combustibility

combustibleness and combustibility both are nouns.

Word	Noun	Adjective	Verb	Adverb
combustibleness	Yes	No	No	No
combustibility	Yes	No	No	No

As nouns, combustibleness and combustibility are synonyms defined as:

combustibleness and combustibility: the quality of being capable of igniting and burning

Other synonyms of combustibleness include burnability.

combustibleness (noun)	combustibility (noun)
the quality of being capable of igniting and burning	the quality of being capable of igniting and burning