The name 'James, masc. proper name, name of two of Christ's disciples, late 12c. M.E. vernacular form of L.L. Jacomus (cf. O.Fr. James, Sp. Jaime, It. Giacomo), altered from L. Jacobus (see 'Jacob')
The name 'Jacob', masc. proper name, name of O.T. patriarch, son of Isaac and Rebecca and father of the founders of the twelve tribes, from L.L. Jacobus, from Gk. Iakobos, from Heb. Ya'aqobh, lit. "one that takes by the heel" (Gen. xxviii.12), a derivative of 'aqebh "heel."