noun

• (uncountable) Recognition of the distinction between good and evil or between right and wrong; respect for and obedience to the rules of right conduct; the mental disposition or characteristic of behaving in a manner intended to produce morally good results.
• (countable) A set of social rules, customs, traditions, beliefs, or practices which specify proper, acceptable forms of conduct.
• (countable) A set of personal guiding principles for conduct or a general notion of how to behave, whether respectable or not.
• (countable, archaic) A lesson or pronouncement which contains advice about proper behavior.
• (countable) A morality play.
• (uncountable, rare) Moral philosophy, the branch of philosophy which studies the grounds and nature of rightness, wrongness, good, and evil.
• (countable, rare) A particular theory concerning the grounds and nature of rightness, wrongness, good, and evil.