What do you call a place to sleep when you’re half asleep?
Well, sure, berrum, I suppose, as in “Whayya doon immy berrum?” But I mean something simultaneously more and less fancy: dorter, as in “Gwan gi outa my dorter.” It’s more fancy because it’s Latin-derived, and less fancy because, well, a dormitory is less fancy than a bedroom. But also, it’s simultaneously both because it’s especially associated with monks.
Anyway, berrum isn’t officially a word and no one would understand it without context (or perhaps even with context). You have to go with bedroom. But dorter is a word, and it’s been an English word longer than dormitory has.
How can that be? How can the worn-down form precede the full form? Just because it got worn down in French, and then the un-worn-down form was brought in later on. Sort of like how you might get introduced to blended Scotch before you come to know the single-malt kind.
The Latin original is dormitorium, which is a place for sleeping like a scriptorium is a place for writing and a crematorium is a place for being burned. It went into Old French and became dortoir, also spelled dortour, which is also another way we can spell our English word dorter. That word came over to English in the late 1200s, when monks were common and had separate sleeping-places while other common people didn’t always. So dorter became associated with monasteries – ironically, because no Englishman would ever send his dorter to a monastery (that’s a pun, see, because in a typical modern British accent dorter and daughter sound the same).
And dormitory came into English about 200 years later, also first to do with monasteries. It wasn’t until the 1800s in the US that the term came to be associated with university student residences. Bedroom, by the way, has been with us at least since Shakespeare used the word in 1600s; it supplanted the earlier bedchamber, present since the later 1300s and now long restricted to royals, who at the time of its introduction were more likely to have them anyway.
The English language, as it passed through the Renaissance, was a bit like a sleepy student gradually coming awake to find his Latin and Greek tutors at the foot of his bed. It had all these inheritances by way of French (since the French ran the place for a while after 1066 and all that), but once it became aware of its glorious classical roots – and wanted to be thought not inattentive but appreciative of its noble roots – it started striving to make more of them. And education became more and more available to broader segments of society – not just for the sleepy monks in their dorters, but for the diligent (ha!) students in their dormitories.