English

energy vampire

From energy + vampire.

Proto-Indo-European *werǵ- ‘to make’

…

Ancient Greek ἐνεργός ‘active’

Ancient Greek ἐνέργεια ‘activity’

Late Latin energia

Middle French énergie

German Vampir

French vampire

Today it means

noun A device or appliance that uses electricity even while switched off.

Language periods are conventional ranges, not dates for this word.

Etymograph / energy vampire