What is the X in X-mas?
c.1200, "room," usually a private one, from Old French chambre "room, chamber, apartment," also used in combinations to form words for "latrine, privy" (11c.), from Late Latin camera "a chamber, room" (see camera). In anatomy from late 14c.; of machinery from 1769. Gunnery sense is from 1620s. Meaning "legislative body" is from c.1400. Chamber music (1789) was that meant to be performed in private rooms instead of public halls.
late 14c., "to restrain," also "to furnish with a chamber" (inplied in chambered, from chamber (n.). Related: Chambering.
chamber cham·ber (chām'bər)
A compartment or enclosed space.
"on the wall," which the Shunammite prepared for the prophet Elisha (2 Kings 4:10), was an upper chamber over the porch through the hall toward the street. This was the "guest chamber" where entertainments were prepared (Mark 14:14). There were also "chambers within chambers" (1 Kings 22:25; 2 Kings 9:2). To enter into a chamber is used metaphorically of prayer and communion with God (Isa. 26:20). The "chambers of the south" (Job 9:9) are probably the constelations of the southern hemisphere. The "chambers of imagery", i.e., chambers painted with images, as used by Ezekiel (8:12), is an expression denoting the vision the prophet had of the abominations practised by the Jews in Jerusalem.