noun

1. a knowledge or sense of right and wrong, with an urge to do right; moral judgment that opposes the violation of a previously recognized ethical principle and that leads to feelings of guilt if one violates such a principle
2. Obsolete
   1. consciousness
   2. inner thoughts or feelings

Etymology: OFr < L conscientia, consciousness, moral sense < prp. of conscire < com-, with + scire, to know (see science): replacing ME inwit, knowledge within