The crossword solution for the term 'A Jealous Mistress, Per Emerson' is ART. This is a reference to Ralph Waldo Emerson's poem 'The Rhodora, ' which contains the line 'On being asked, Whence is the flower? / The rose is fair, replied the maiden / It was the dust of Proserpine's bright door / Tinged by the atmosphere of Jove's jealous mistress.' In this poem, Emerson is referring to the Greek goddess Persephone, who was the daughter of Demeter and the wife of Hades, and was known as the jealous mistress of the god Jupiter.