After John Bercow refused a third “meaningful vote” on Theresa May’s Brexit agreement this week, some politicians hatched a cunning plan for a “prorogation” of parliament to bring it back. People who wish to be seen as constitutional experts like to bandy about such terms, but what does this one actually mean?

Confusingly, prorogation is one of those words that seems to mean either x or the opposite of x. Its primary sense is prolongation, from the Latin for extension or postponement. In politics, though, it means to discontinue meetings of an assembly and start a new session later. Doesn’t that mean cutting it short? That is what one 17th-century writer thought, complaining: “What a Noise it made, the Chopping Parliaments off, by Prorogations.”

But, looked at another way, a prorogation really is a prolongation, as Sir William Blackstone’s Commentaries on the Laws of England explained in 1765: “A prorogation is the continuance of the parliament from one session to another.” Can we think of another phenomenon that means one thing to some people and another thing to others? Happily, Brexit itself could be subject to prorogation in its third sense, of deferring something to a hopefully brighter future.