high life vs highlife

high life and highlife both are nouns.

Word	Noun	Adjective	Verb	Adverb
high life	Yes	No	No	No
highlife	Yes	No	No	No

As nouns, high life and highlife are synonyms defined as:

Other synonyms of high life include extravagance, lavishness, prodigality.

high life (noun)	highlife (noun)
the activity of excessive spending	the activity of excessive spending