a.
1.
Mighty, potent, puissant.
2.
Vigorous, robust, sturdy, strong, able-bodied, muscular, sinewy, nervous.
3.
Of great power, commanding, able, over-powering, dominating, forcible, forceful.
4.
Efficacious, effective, efficient, effectual, energetic, operative, influential, cogent, valid.