Powerfully means with great force or effect. Powerfully built, argued powerfully, powerfully moving.
Powerfully built is the fixed phrase for a heavy muscular frame, and it is a polite one. Of an argument it means the case landed rather than that it was loud.
1adverbpowerfullyWith great force or effect.
“The river flowed powerfully after the storm, carrying away trees and fences.”
powerfully is a manner.
Middle English
pouerful
English
powerful
English, today
powerfully
From powerful + -ly. powerful comes from Middle English pouerful, powarfull. by surface analysis, power + -ful.
Etymology from Wiktionary, CC BY-SA