ill luck vs bad luck

ill luck and bad luck both are nouns.

Word	Noun	Adjective	Verb	Adverb
ill luck	Yes	No	No	No
bad luck	Yes	No	No	No

As nouns, ill luck and bad luck are synonyms defined as:

ill luck and bad luck: an unfortunate state resulting from unfavorable outcomes

Other synonyms of ill luck include misfortune, tough luck.

ill luck (noun)	bad luck (noun)
an unfortunate state resulting from unfavorable outcomes	unnecessary and unforeseen trouble resulting from an unfortunate event
	an unpredictable outcome that is unfortunate
	an unfortunate state resulting from unfavorable outcomes