n (physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs
n forceful exertion
n enterprising or ambitious drive
n an imaginative lively style (especially style of writing)
n a healthy capacity for vigorous activity
n any source of usable power
n the federal department responsible for maintaining a national energy policy of the United States; created in 1977
