Drastic
Part of speech: adjective
Definition: Extreme, severe. Acting rapidly or violently. Extremely severe or extensive.
Example sentence: I had to make a drastic change at Sun Records and I didn't really appreciate country music until I went there.
Forceful
Part of speech: adjective
Definition: With assertive force; powerful.
Example sentence: I can assure you we are all strong-willed, forceful personalities and the president encourages vigorous debate.