Jealous (def.)

(jel'), a. [ME, jelous, gelous; OFr. jalous, from LL zelosus, full of zeal, from L. zelus; Gr. zelos, zeal, emulation.]

1. suspicious; apprehensive of rivalry; as, her husband was jealous of the other man.
2. resulting from such a feeling; as, a jealous rage.
3. demanding exclusive loyalty; as, the Lord is a jealous God.
4. resentfully envious.
5. careful in protecting; watchful; solicitous; as, jealous of one's reputation.
6. doubtful [Obs.]
Syn. -- envious, covetous, invidious, suspicious.

-- from Webster's New Universal Unabridged Dictionary, deluxe 2nd ed.