jeal·ous / ˈjeləs/ • adj. feeling or showing envy of someone or their achievements and advantages: he grew jealous of her success. ∎  feeling or showing suspicion of someone's unfaithfulness in a relationship: a jealous boyfriend. ∎  fiercely protective or vigilant of one's rights or possessions: Howard is still a little jealous of his authority they kept a jealous eye over their interests. ∎  (of God) demanding faithfulness and exclusive worship.DERIVATIVES: jeal·ous·ly adv.

jealous suspicious of rivalry XIII; zealous (for) XIV; (dial.) suspicious XVI; suspiciously vigilant XVII. ME. gelus, ielus — OF. gelos (mod. jaloux) :- medL. zēlōsus, f. ChrL. zēlus — Gr. zˇelos ZEAL see -OUS.
So jealousy XIII.