Jealousy

wiktionary

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From Middle English jalousie, from Old French jalousie, see jealous, -y. Doublet of jalousie. Related also to zeal, zealous.

etymonline

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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.