Favourite Legal Words and Expressions

The Law Library of Congress in Washington recently conducted a survey of its staffers to find out what their favorite legal terms or phrases are and why.

Among the results are:

  • in custodia legis
  • proprio motu
  • amicus curiae
  • res ipsa loquitur
  • estoppel
  • force majeure
  • Miranda warning
  • pettifogger (!)

One employee’s entry was for “in loco parentis”:

In loco parentis [in place of parents]. When I see this term, I see not the Latin word for “place” but the Spanish word for “crazy,” as in “parents make you crazy” or “in parenthood, craziness.” I think of this term whenever my four year-old complains about having parents instead of robots to raise him. (Robots, apparently, allow ice cream to be a main dinner course and don’t enforce rules!)

The Law Library of Congress is the world’s largest law library, with a collection of over 2.65 million volumes from all ages of history and virtually every jurisdiction in the world.


  1. My wife and I are fond of ‘incorporeal heriditaments’, though we are not sure if we have any.

    ‘Messuages and tenements’ would run a close second in our favours.

    The lingering (decades later) impact of strong professors of land law, I guess.

  2. I probably didn’t giggle as much reading legal Latin out of Black’s as I did reading swears in Webster’s as a child, but it was close.

    A couple personal favourites:

    *delegatus non potest delegare (a lesson I learned when trying to hand-off to another some work that was assigned to me)

    *nunc pro tunc (a habit I employ when asserting the retrospective validity house rules I declare my kids to have broken when they claim to have been unfamiliar with the rule)

  3. – spoliation (which sounds particularly good when Saul Goodman says it)
    – the one free bite law (I love this one as a dog owner)
    – sua sponte (I don’t know what it means but it sounds wet)

  4. Those interested in Latin phrases may enjoy the case of Rex v. Venables. In this case, an English Lord Chief Justice decided that the courts would not tolerate lawyers pronouncing Latin phrases in any way other than according to the courts’ immemorial practice. “In the legal profession, above all others, the Latin tongue is a living force, a priceless aid to precision of thought, to verbal economy and practical efficiency.” However, although the courts have taken many words from Rome, they pronounce them in English, as the expressions ultra vires, status quo and per centum show. The case is among a collection of humorous cases in Uncommon Law by A.P. Herbert, 1935.