celestial orbit vs itinerary

celestial orbit and itinerary both are nouns.

Word	Noun	Adjective	Verb	Adverb
celestial orbit	Yes	No	No	No
itinerary	Yes	No	No	No

As nouns, itinerary is a hypernym of celestial orbit; that is, itinerary is a word with a broader meaning than celestial orbit:

celestial orbit: the (usually elliptical) path described by one celestial body in its revolution about another
itinerary: an established line of travel or access

Other hypernyms of celestial orbit include path, route.

celestial orbit (noun)	itinerary (noun)
the (usually elliptical) path described by one celestial body in its revolution about another	a proposed route of travel
	a guidebook for travelers
	an established line of travel or access