5. (Arch.) An abrupt interruption of level in a piece of brickwork or
masonry.
From the jump, from the start or beginning. [Colloq.] -- Jump joint.
(a) A butt joint. (b) A flush joint, as of plank in carvel-built
vessels. -- Jump seat. (a) A movable carriage seat. (b) A carriage
constructed with a seat which may be shifted so as to make room for
second or extra seat. Also used adjectively; as, a jump-seat wagon.
Jump, a. Nice; exact; matched; fitting; precise. [Obs.] "Jump names."
B. Jonson.
Jump, adv. Exactly; pat.[Obs.] Shak.
Jump"er (?), n. 1. One who, or that which, jumps.