remark vs observance

remark and observance both are nouns.

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

As nouns, observance is a hypernym of remark; that is, observance is a word with a broader meaning than remark:

Other hypernyms of remark include notice, observation.

remark (noun)	observance (noun)
explicit notice	the act of observing; taking a patient look
a statement that expresses a personal opinion or belief or adds information	conformity with law or custom or practice etc.
	the act of noticing or paying attention
	a formal event performed on a special occasion

remark (verb)	observance (verb)
make mention of
make or write a comment on