\u201cJumper\u201d is actually derived from the noun \u201cjump,\u201d a modified form of the French \u201cjupe,\u201d used to mean a short coat in the 19th century (and completely unrelated to \u201cjump\u201d meaning \u201cleap\u201d). ... The use of \u201csweater\u201d in its modern sense of \u201cheavy knitted top worn for warmth\u201d had appeared by the early years of the 20th century.