Prorogue
Adjourn an assembly without discontinuing it.
Last night I was reading The Glorious Cause: The American Revolution, 1763 – 1789 when I came across this word, in a sentence referring to the prorogue of Parliament in (I think) 1766. Usually when I come across a word that is new to me I have some idea what it might mean from the context or familiar roots, but this one was entirely new to me.