ethics, especially that branch dealing with duty, moral obligation, and right action.
Origin: 1820–30; < Greek deont- that which is binding (stem of déon, neuter present participle of deîn to bind), equivalent to de- bind + -ont- present participle suffix + -o- + -logy
philosophy (of an ethical theory) regarding obligation as deriving from reason or as residing primarily in certain specific rules of conduct rather than in the maximization of some good