1766, French, literally "jealousy" (see jealousy), from notion of spying through blinds without being seen.
Entries linking to jalousie
jealousy n.
c. 1200 in reference to sexual possessiveness and suspicion, from Old French jalousie "enthusiasm, love, longing; jealousy" (12c.), from jalos "keen, zealous; avaricious; jealous" (see jealous). Also sometimes in Middle English in a sense "solicitude, carefulness, regard," the connecting notion being "watchfulness." Meaning "zeal, fervor, devotion" is from late 14c.