The Law's Latin

Roman legal Latin that never left the courtroom — or the boardroom.

• bona fide IDIOM Genuine and honestly meant — the real thing, not a pretence. The Roman standard of good faith.
• caveat emptor IDIOM Let the buyer beware — checking what you are buying is your own problem. What Rome did not actually say.
• quid pro quo IDIOM Something given in return for something else, usually as an understood trade. From the apothecary's substitute.
• de facto IDIOM In practice, whatever the official position says. The question of fact.
• de jure IDIOM According to the law, whether or not that is what actually happens. The question of law.
• ipso facto IDIOM By that very fact — the consequence follows automatically, with no further step. Consequences that need no hearing.
• the status quo IDIOM The way things currently are, especially when someone wants to keep them that way. In statu quo ante bellum.
• ad hoc IDIOM Made for this one situation, with no general rule behind it. For this case only.
• cui bono IDIOM Who benefits? — asked to find out who is really behind something. The judge Cassius's question.
• ignorance of the law is no excuse IDIOM Not knowing a rule existed will not get you out of having broken it. Straight out of the Digest.
• modus operandi IDIOM A person's characteristic way of doing something, recognisable across occasions. How the thing was done.
• persona non grata IDIOM Someone who is no longer welcome, and has been told so. Vienna Convention, Article 9.