observant vs observe

observant is an adjective but observe is not an adjective.

Word	Noun	Adjective	Verb	Adverb
observant	No	Yes	No	No
observe	No	No	Yes	No

observant (adjective)	observe (adjective)
paying close attention especially to details
(of individuals) adhering strictly to laws and rules and customs
quick to notice; showing quick and keen perception

observant (verb)	observe (verb)
	stick to correctly or closely
	make mention of
	watch attentively
	observe with care or pay close attention to
	discover or determine the existence, presence, or fact of by perception with the eyes
	follow with the eyes or the mind
	show respect towards
	behave as expected during of holidays or rites
	conform one's action or practice to