- governed by conscience; controlled by or done according to one’s inner sense of what is right; principled: She’s a conscientious judge, who does not let personal prejudices influence her decisions.
- careful and painstaking; particular; meticulous; scrupulous: conscientious application to the work at hand.
- involving or taking great care; painstaking; diligent
- governed by or done according to conscience
adj.1610s, from Middle French conscientieux (16c.; Modern French consciencieux), from Medieval Latin conscientiosus, from conscientia (see conscience). Related: Conscientiously; conscientiousness.