good fortune vs luck

good fortune and luck both are nouns.

Word	Noun	Adjective	Verb	Adverb
good fortune	Yes	No	No	No
luck	Yes	No	No	No

As nouns, luck is a hypernym of good fortune; that is, luck is a word with a broader meaning than good fortune:

good fortune: a stroke of luck
luck: an unknown and unpredictable phenomenon that leads to a favorable outcome

Other hypernyms of good fortune include fortune.

As nouns, luck is a hypernym of good fortune; that is, luck is a word with a broader meaning than good fortune:

good fortune: an auspicious state resulting from favorable outcomes
luck: your overall circumstances or condition in life (including everything that happens to you)

Other hypernyms of good fortune include circumstances, destiny, fate, fortune, lot, portion.

good fortune (noun)	luck (noun)
a stroke of luck	an unknown and unpredictable phenomenon that causes an event to result one way rather than another
an auspicious state resulting from favorable outcomes	an unknown and unpredictable phenomenon that leads to a favorable outcome
	your overall circumstances or condition in life (including everything that happens to you)