Meaning

noun (physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs

noun forceful exertion

noun enterprising or ambitious drive

originEtymology tree Proto-Indo-European *h₁én Ancient Greek ἐν (en) Ancient Greek ἐν- (en-) Proto-Indo-European *werǵ- Proto-Indo-European *-om Proto-Indo-European *wérǵom Proto-Hellenic *wérgon Ancient Greek ἔργον (érgon) Proto-Indo-European *-os Proto-Hellenic *-os Ancient Greek -ος (-os) Ancient Greek ἐνεργός (energós) Proto-Indo-European *-os Proto-Indo-European *-ēs Ancient Greek -ης (-ēs)…

Etymology from Wiktionary, CC BY-SA 3.0