Etymology
Advertisement
mitre (n.)

mid-14c., "bishop's tall hat," from Old French mitre and directly from Latin mitra "headband, turban," from Greek mitra "headband, turban," earlier a belt or cloth worn under armor about the waist, perhaps from PIE root *mei- "to bind, attach" (source also of Sanskrit mitra- "friend, friendship," Old Persian Mithra-, god name; Russian mir "world, peace"). The Greek word might be borrowed from Indo-Iranian.

In pre-Christian Latin, in reference to a type of head-dress anciently worn by inhabitants of Lydia, Phrygia, and other parts of Asia Minor, "the wearing of which by men was regarded in Rome as a mark of effeminacy" [OED]. But the word was used in Vulgate to translate Hebrew micnepheth, the sacerdotal head-dress of the ancient Jewish high priests.

Related entries & more 
Advertisement
joint (adj.)
early 15c., "united or sharing" (in some activity), from Old French jointiz (adj.) "joined together, close together" and Old French joint (14c.), past-participle adjective from joindre "to join, connect, unite," from Latin iungere "to join together," from nasalized form of PIE root *yeug- "to join."
Related entries & more 
joint (n.)
c. 1300, "an (anatomical) joint, a part of a body where two bones meet and move in contact with one another, the structure that holds such bones together," from Old French joint "joint of the body" (12c.), from Latin iunctus "united, connected, associated," past participle of iungere "to join together," from nasalized form of PIE root *yeug- "to join." Related: Joints.

In general use from late 14c., of insect and plant parts, also "that which joins two components of an artificial structure." In butchering, "cut of meat on the bone," early 15c. Slang or cant meaning of "place, building, establishment" (especially one where persons meet for shady activities) first recorded 1877; earlier it was used in an Anglo-Irish context (1821), perhaps on the notion of a private side-room, one "joined" to a main room. In late 19c. U.S. use especially "an opium-smoking den" (1883).

Meaning "marijuana cigarette" (1938) is perhaps from notion of something often smoked in common, but there are other possibilities; earlier joint in drug slang meant "hypodermic outfit" (1935). Meaning "prison" is attested from 1953 but probably is older. Out of joint in the figurative sense "disordered, confused, gone wrong" is from early 15c. (literally, of bone displacement, late 14c.). Joint-stock "of or pertaining to holding stock in shares" is from 1610s.
Related entries & more 
miter (n.2)

in carpentry, "a joint at a 45 degree angle," 1670s, of uncertain origin, perhaps from mitre, via notion of joining of the two peaks of the folded cap. As a verb, to make or join with a miter-joint," from 1731. Related: Mitered. Miter-box is attested from 1670s.

Related entries & more 
mitral (adj.)

c. 1600, "resembling a mitre, of or pertaining to a mitre," from French mitral, from Modern Latin mitralis, from Latin mitra (see mitre). The mitral valve of the heart is so called from 1705, from Modern Latin mitrales valvulae.

Related entries & more 
Advertisement
miter (n.1)

in reference to a type of head-dress, an alternative spelling of mitre (see -re).

Related entries & more 
arthroscopy (n.)

"surgical procedure for joint problems that involves insertion of a narrow tube in the joint," by 1977, from arthro- + -scopy.

Related entries & more 
vertebrate (n.)
"a vertebrate animal," 1826, from Latin vertebratus (Pliny), from vertebra "joint or articulation of the body, joint of the spine" (see vertebra). As an adjective also from 1826.
Related entries & more 
disarticulate (v.)

1808, transitive, "undo the articulation of, separate joint from joint;" see dis- "reverse, opposite of" + articulate (v.). Intransitive sense of "become separated, lose articulation" is by 1830. Related: Disarticulated; disarticulating.

Related entries & more 
arthralgia (n.)
"pain in a joint," 1848, earlier in French and German, from Greek arthron "joint" (from PIE root *ar- "to fit together") + -algia "pain." Related: Arthralgic.
Related entries & more