As used in the scriptures, the word jealous has two meanings:¹ to be fervent and to have sensitive and deep feelings about someone or something, and² to be envious of someone or suspicious that another will gain some advantage.

To have fervent feelings: I the Lord am a jealous God, Ex. 20: 5 (Deut. 5: 9; 6: 15; Mosiah 11: 22). I will be jealous for my holy name, Ezek. 39: 25. I am jealous for Jerusalem and for Zion, Zech. 1: 14.

To be envious or suspicious: Jealousy is the rage of a man, Prov. 6: 32-35. Akish began to be jealous of his son, Ether 9: 7. Strip yourselves from jealousies and fears, D&C 67: 10.