1. (n.) energy; pep.

2. (n.) courage, determination.

3. (n.) Know-how, expertise.

amperage animation armipotence authority backbone beef birr black power bottom breeziness briskness brute force bubbliness charge charisma clout cogence cogency compulsion courage dauntlessness dint drive duress ebullience effect effectiveness effectuality effervescence energy flower power force force majeure forcefulness full blast full force gameness go grit guts hardihood heart influence intestinal fortitude life liveliness main force main strength mana mettle mettlesomeness might might and main mightiness muscle power nerve pep peppiness piss and vinegar pith pizzazz pluck pluckiness poop potence potency potentiality power power pack power structure power struggle powerfulness prepotency productiveness productivity puissance pull punch push resolution sand sinew spirit spiritedness sprightliness spunk spunkiness stamina steam strength strong arm superiority superpower toughness true grit tuck validity vehemence verve vigor vim virility virtue virulence vitality vivaciousness vivacity wattage weight