Jumper
mid 19th century (in jumper1 (sense 2 of the noun)): probably from dialect jump ‘short coat’, perhaps from Scots jupe ‘a man's (later also a woman's) loose jacket or tunic’, via Old French from Arabic jubba . Compare with jibba.
wiktionary
jump + -er
From the term jump(“short coat”) in sailors' jargon, probably from Scots English jupe(“man's loose jacket or tunic”), from Old French, from Arabic جُبَّة (jubba); see also jibba. Cognate with German Joppe.
etymonline
jumper (n.1)
"one who jumps," 1610s, agent noun from jump (v.). In basketball, "jump-shot," from 1934. The meaning "basket on an elastic cord permitting a small child to push off the floor" is short for baby-jumper (1848).
jumper (n.2)
article of clothing, 1853, in reference to a kind of loose jacket with sleeves, apparently from mid-17c. jump (n.) "short coat worn by men," also "woman's under-bodice," a word of uncertain origin. It is perhaps from French jupe "skirt" (see jupe) or from some notion in jump (v.). Meaning "sleeveless dress worn over a blouse" is from 1967, short for jumper-dress (1907).