Survey of English Place-Names

Etymology

Jump Lum (lost), 1768 PR (where a man was drowned, op. cit. 263), v. lumm 'pool'. In 1710 PR 100 it is recorded that 'William Chapelhow, an idiot, drowned in a small pool of back water (since called Jump Hole ) at Sackwath head; the poor innocent went by the name of Willy Jump'. The first el. may be e.ModE  jumpe 'a jump', used of an 'abrupt descent', 'a jumping place', or the like (cf. Jumps YW iii, 173).