morning vs good morning

morning and good morning both are nouns.

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

As nouns, morning and good morning are synonyms defined as:

morning and good morning: a conventional expression of greeting or farewell, used to wish someone a good morning

morning (noun)	good morning (noun)
a conventional expression of greeting or farewell, used to wish someone a good morning	a conventional expression of greeting or farewell, used to wish someone a good morning
the earliest period
the time period between dawn and noon
the first light of day