morning vs farewell

morning and farewell both are nouns.

Word	Noun	Adjective	Verb	Adverb
morning	Yes	No	No	No
farewell	Yes	No	No	No

As nouns, farewell is a hypernym of morning; that is, farewell is a word with a broader meaning than morning:

morning: a conventional expression of greeting or farewell, used to wish someone a good morning
farewell: an acknowledgment or expression of goodwill at parting

Other hypernyms of morning include word of farewell, greeting, salutation.

morning (noun)	farewell (noun)
a conventional expression of greeting or farewell, used to wish someone a good morning	the act of departing politely
the earliest period	an acknowledgment or expression of goodwill at parting
the time period between dawn and noon
the first light of day