bra

Etymology 1

Clipping of brassiere, borrowed from French brassière, from Old French braciere (originally a lining inside armor to protect the arm, but later a garment), from Old French brace (“arm”), from Latin bracchia, plural of Latin bracchium (“forearm”), from Ancient Greek βραχίων (brakhíōn, “forearm”), from Proto-Hellenic *brəkʰús (“short”) (because the forearm is shorter than the upper arm), inherited from Proto-Indo-European *mréǵʰus.

noun

1. An item of underwear worn to support the breasts.
   Her housecoat had fallen open. She was wearing only panties and bra, which did nothing to make her scrawny, wrinkled body appealing. 1968, Carl Ruhen, The Key Club, Sydney: Scripts, page 12

Etymology 2

From bracket, referring to the notation introduced in 1939 by Paul Dirac.

noun

1. (physics) One of the two vectors in the standard notation for describing quantum states in quantum mechanics, the row vector; the other (column) vector being its complex conjugate, the ket.

Etymology 3

PIE word *bʰréh₂tēr Representing a different pronunciation of bro (“brother”).

noun

1. (slang) Alternative form of bro; friend, mate
   Take it easy, bra!
   “Famalam, I ain't even gon lie to ya man, I am super happy to be finally maxing out on parole my real. This violation was definitely a reality check Bra!” Influence replied to his comrade. 2009, Todd Johnson, Influence