earliness vs early

earliness is a noun but early is not a noun.

Word	Noun	Adjective	Verb	Adverb
earliness	Yes	No	No	No
early	No	Yes	No	Yes

earliness (noun)	early (noun)
quality of coming early or earlier in time

earliness (adjective)	early (adjective)
	at or near the beginning of a period of time or course of events or before the usual or expected time
	of an early stage in the development of a language or literature
	being or occurring at an early stage of development
	belonging to the distant past
	very young
	expected in the near future

earliness (adverb)	early (adverb)
	before the usual time or the time expected
	during an early stage
	in good time