apology vs instance

apology and instance both are nouns.

Word	Noun	Adjective	Verb	Adverb
apology	Yes	No	No	No
instance	Yes	No	Yes	No

As nouns, instance is a hypernym of apology; that is, instance is a word with a broader meaning than apology:

Other hypernyms of apology include example, illustration, representative.

apology (noun)	instance (noun)
a poor example	an item of information that is typical of a class or group
an expression of regret at having caused trouble for someone	an occurrence of something
a formal written defense of something you believe in strongly

apology (verb)	instance (verb)
	clarify by giving an example of