To jump or to fit or unite with like a graft; as, both our inventions meet and jump in one. Hence the adverb exactly, precisely.
“Good advice is easily followed when it jumps with our own … inclinations.”—Lockhart: Sir Walter Scott, chap. x. p. 241
⁂ The Scotch use jimp, as, “When she had been married jimp four months” (The Antiquary.)