Etymology Dictionary

JAMB,  the side-post of a door.  (F.,—L.)   'Jawm of the door, the side-post.   The word is also in use in the South, where they say the jaum of the chimney;' Ray, Collection of North-Country Words, 1691.   Spelt jaumbe in Cotgrave.   'Yea, the jambes, posts, principals, and standards, all of the same mettall;' Holland, tr. of Pliny, b. xxxiii. c. 3.—F. jambe, 'the leg or shank,... the jaumbe or side-post of a door;' Cot.   Cf. Ital. gamba, Span. gamba, the leg; Port. gambias, pl. the legs.—Late Lat. gamba, a hoof; Vegetius, I. 56, near the end; 3. 20.   This is certainly a corruption from an older form camba, which appears in O. Spanish (Diez, whom see).—✔KAM, to bend; whence Lat. camurus, crooked, camera, a vault; so that the word was orig. used of the bent leg or the knee.   Cf. W. cam, crooked.   And see Chamber, Gambol, Ham.   Der. giamb-eux, leggings, greaves, Spenser, F. Q. ii. 6. 29 (apparently a coined word).