definition of
energy

[1] #1 energy n. [free energy] (physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs; "energy can take a wide variety of forms". wn

[2] #2 energy n. [vigor, vigour, zip] forceful exertion; "he plays tennis with great energy"; "he's full of zip". wn

[3] #3 energy n. [push, get-up-and-go] enterprising or ambitious drive; "Europeans often laugh at American energy". wn

[4] #4 energy n. [muscularity, vigor, vigour, vim] an imaginative lively style (especially style of writing); "his writing conveys great energy"; "a remarkable muscularity of style". wn

[5] #5 energy n. [vim, vitality] a healthy capacity for vigorous activity; "jogging works off my excess energy"; "he seemed full of vim and vigor". wn