profit margin vs gross margin

profit margin and gross margin both are nouns.

Word	Noun	Adjective	Verb	Adverb
profit margin	Yes	No	No	No
gross margin	Yes	No	No	No

As nouns, profit margin and gross margin are synonyms defined as:

profit margin and gross margin: the ratio gross profits divided by net sales

Other synonyms of profit margin include margin of profit.

profit margin (noun)	gross margin (noun)
the ratio gross profits divided by net sales	the ratio gross profits divided by net sales