margin of profit vs gross margin

margin of profit and gross margin both are nouns.

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

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

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

Other synonyms of margin of profit include profit margin.

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