Meaning

noun motivation deriving logically from ethical or moral principles that govern a person's thoughts and actions

noun conformity to one's own sense of right conduct

noun a feeling of shame when you do something immoral

originFrom Middle English conscience, from Old French conscience, from Latin conscientia (“knowledge within oneself”), from consciens, present participle of conscire (“to know, to be conscious (of wrong)”), from com- (“together”) + scire (“to know”).

Etymology from Wiktionary, CC BY-SA 3.0