Jealousy
Etymology
From Old French "jalousie," from Late Latin "zelosus," from Greek "zēlos" — "zeal, ardor, fervor." Jealousy and zeal are the same word: both name a burning intensity. The English "jealous" and "zealous" split apart from a single ancestor, one turning suspicious, the other devoted.
noun · /JEL-uh-see/
The anxious fear of losing something or someone you have to a rival.
What it names
Use it for the guarding emotion — the vigilance that flares when a valued bond feels threatened by a third party.
Example
His jealousy surfaced whenever she mentioned the charming new coworker.
Related idea
Against envy: jealousy protects possession against a threat (a love triangle); envy covets a possession you never had. Tellingly, we say a “jealous God” and a “jealous guardian” — jealousy can be righteous guarding, where envy is only ever a lack.
See also