the force or strength (of arguments)

effectiveness

the skilful use of language to express oneself or persuade others

skilful way with words

(of a person) the force, strength, capacity, to do things and get things done

person's spirit and vigor

the state, quality, of being intense; strength (of feeling etc)

passion, force

great effort, power, strength; of may

ability, power

enthusiasm, spirit, vigour (especially in artistic or literary work)

energy, enthusiasm

(an amount of) electrical force measured in volts

physical ability, capacity