Words related to jealous

zeal (n.)

"passionate ardor in pursuit of an objective or course of action," late 14c., from Old French zel (Modern French zèle) and directly from Late Latin zelus "zeal, emulation" (source also of Italian zelo, Spanish celo), a Church word, from Greek zēlos "ardor, eager rivalry, emulation," "a noble passion" [Liddell & Scott], but also "jealousy;" from PIE *ya- "to seek, request, desire." From mid-15c. as "devotion."

zealous (adj.)
"full of zeal" (in the service of a person or cause), 1520s, from Medieval Latin zelosus "full of zeal" (source of Italian zeloso, Spanish celoso), from zelus (see zeal). The sense "fervent, inspired" was earlier in English in jealous (late 14c.), which is the same word but come up through French. Related: Zealously, zealousness.
jealously (adv.)
late 14c., "in a zealous manner;" 1718, "in a suspicious and possessive manner," from jealous + -ly (2).
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.