(law) ex post facto law, retroactive law

system; institution

after an event / (euphemistic) after sex

fair / just

fairness / justice

the field, profession, and study of law. The rule of law / a statute / an act of a legislature

law / measure, size

question, problem on homework etc. / a question; a matter (of time etc.) / a problem (something that needs to be dealt with); a trouble / an issue; a matter

feudalism (social system)

A social system; regime.