adjective

1. having to do with ethics or morality; of or conforming to moral standards
2. conforming to the standards of conduct of a given profession or group
3. designating or of a drug obtainable only on a doctor's prescription

Etymology: ME ethik (< L ethicus < Gr ēthikos < ēthos, character, custom < IE base *swedh-, essential quality, own character > Goth swes, L suus, one's own & suescere, to become accustomed) + -al