See potency in Webster's New World Roget's A-Z Thesaurus II
The state or quality of being physically strong:
brawn, might, muscle, potence, power, powerfulness, puissance, sinew, strength, thew (often used in plural). See strongCapacity or power for work or vigorous activity:
animation, energy, force, might, power, puissance, sprightliness, steam, strength. (Informal) get-up-and-go, go, pep, peppiness, zip. See actionThe power or capacity to produce a desired result:
effect, effectiveness, effectuality, effectualness, efficaciousness, efficacy, efficiency, influence. See affectLearn more about potency