The word chamber was borrowed around the beginning of the 1100s from the Old French word chambre, which comes from Latin camera, which had the same definition but also had a specific connotation of the rooms having vaulted ceilings. That's from Greek kamara, which described anything with an arched cover, and kamara in turn is reconstructed as deriving from the Proto-Indo-European root khem, meaning "bend" or "curve". If you noticed the word camera and wondered if there's any relation to photography, there actually is: our modern word is actually a clipping of the Latin phrase camera obscura, which meant "dark chamber", because the first cameras used a dark room and a pinhole. According to Google NGrams, usage of the word camera peaked in the early 2000s and is now in decline.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.