flammability vs inflammability

flammability and inflammability both are nouns.

Word	Noun	Adjective	Verb	Adverb
flammability	Yes	No	No	No
inflammability	Yes	No	No	No

As nouns, flammability and inflammability are synonyms defined as:

flammability and inflammability: the quality of being easily ignited and burning rapidly

flammability (noun)	inflammability (noun)
the quality of being easily ignited and burning rapidly	the quality of being easily ignited and burning rapidly