adj. 1 (often foll. by of) fiercely protective (of rights etc.). 2 afraid, suspicious, or resentful of rivalry in love or affection. 3 (often foll. by of) envious or resentful (of a person or a person's advantages etc.). 4 (of God) intolerant of disloyalty. 5 (of inquiry, supervision, etc.) vigilant. jealously adv.
[ ME f. OF gelos f. med.L zelosus ZEALOUS ]