abidance vs observance

abidance and observance both are nouns.

Word	Noun	Adjective	Verb	Adverb
abidance	Yes	No	No	No
observance	Yes	No	No	No

As nouns, observance is a hyponym of abidance; that is, observance is a word with a more specific, narrower meaning than abidance:

Other hyponyms of abidance include formality, line, honoring, honouring, keeping.

abidance (noun)	observance (noun)
the act of abiding (enduring without yielding)	the act of observing; taking a patient look
the act of dwelling in a place	conformity with law or custom or practice etc.
acting according to certain accepted standards	the act of noticing or paying attention
	a formal event performed on a special occasion