ethic (n.) Look up ethic at Dictionary.com
late 14c., ethik "study of morals," from Old French etique "ethics, moral philosophy" (13c.), from Late Latin ethica, from Greek ethike philosophia "moral philosophy," fem. of ethikos "ethical," from ethos "moral character," related to ethos "custom" (see ethos). Meaning "moral principles of a person or group" is attested from 1650s.