observe vs keep

observe is not a noun while keep is a noun.

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

As verbs, observe and keep are synonyms defined as:

Other synonyms of observe include maintain.

As verbs, observe and keep are synonyms defined as:

Other synonyms of observe include celebrate.

As verbs, observe and keep are synonyms defined as:

observe (noun)	keep (noun)
	the main tower within the walls of a medieval castle or fortress
	a cell in a jail or prison
	the financial means whereby one lives

observe (verb)	keep (verb)
stick to correctly or closely	prevent (food) from rotting
make mention of	prevent the action or expression of
watch attentively	stick to correctly or closely
observe with care or pay close attention to	maintain by writing regular records
discover or determine the existence, presence, or fact of by perception with the eyes	supply with necessities and support
follow with the eyes or the mind	hold and prevent from leaving
show respect towards	retain possession of
behave as expected during of holidays or rites	look after; be the keeper of; have charge of
conform one's action or practice to	retain rights to
	maintain for use and service
	have as a supply
	store or keep customarily
	stop (someone or something) from doing something or being in a certain state
	allow to remain in a place or position or maintain a property or feature
	conform one's action or practice to
	behave as expected during of holidays or rites
	cause to continue in a certain state, position, or activity
	supply with room and board
	maintain in safety from injury, harm, or danger
	fail to spoil or rot
	continue a certain state, condition, or activity
	to rear