1. (n.) Active strength or force of body or mind; capacity for exertion, physically, intellectually, or morally; force; energy.

2. (n.) Strength or force in animal or force in animal or vegetable nature or action; as, a plant grows with vigor.

3. (n.) Strength; efficacy; potency.

4. (v. t.) To invigorate.

amperage animal spirits animation armipotence authority bang beef bite bitingness black power bounce brio briskness brute force capacity capersomeness charge charisma clout cogence cogency coltishness compulsion cuttingness decisiveness demonic energy dint drive duress dynamism eagerness effect effectiveness effectuality elan endurance energy enthusiasm ergal esprit exuberance flower power force force majeure forcefulness fortitude friskiness frolicsomeness full blast full force gaiety gamesomeness gayness get-up-and-go getup go gusto guts gutsiness haleness hardiness healthiness heartiness impressiveness incisiveness influence intensity intestinal fortitude kinetic energy life liveliness longevity lustihood lustiness main force main strength mana manliness mettle mettlesomeness might might and main mightiness mordancy moxie muscle muscle power muscularity nervosity nervousness obstinacy oomph pep piss and vinegar pith pizzazz playfulness poignancy poop potence potency potential energy potentiality power power pack power structure power struggle powerfulness prepotency productiveness productivity puissance pull punch push resilience robustness rollicksomeness rompishness ruggedness sinew sinewiness skittishness snap soundness spirit spiritedness spirits sportiveness sprightliness spunk stalwartness stamina starch staying power steam sticking power stoutness strength strength of will strenuousness strong arm strong language sturdiness superiority superpower toughness trenchancy validity vehemence verve vigorousness vim virility virtue virulence vitality vivacity wattage weight zealousness zest zestfulness zing zip