equity (n.) Look up equity at Dictionary.com
early 14c., from Old French equite (13c.), from Latin aequitatem (nominative aequitas) "equality, conformity, symmetry, fairness," from aequus "even, just, equal" (see equal (adj.)). As the name of a system of law, 1590s, from Roman naturalis aequitas, the general principles of justice which corrected or supplemented the legal codes.