powerful

UK: /ˈpaʊə^rf^ʊl/ US: /ˈpaʊɚfəl/ ,(pou′ər fəl)

WordReference Random House Learner's Dictionary of American English © 2025

pow•er•ful /ˈpaʊɚfəl/   adj. 

1. of or relating to power:
   one of the most powerful earthquakes ever recorded;
   a powerful grip;
   a powerful drug that made him lose his memory;
   a powerful speech.

pow•er•ful•ly, adv. 

WordReference Random House Unabridged Dictionary of American English © 2025

pow•er•ful  (pou′ər fəl), adj. 

1. having or exerting great power or force.
2. physically strong, as a person:
   a large, powerful athlete.
3. producing great physical effects, as a machine or a blow.
4. potent;
   efficacious:
   a powerful drug.
5. having great effectiveness, as a speech, speaker, description, reason, etc.
6. having great power, authority, or influence;
   mighty:
   a powerful nation.
7. Dialect Terms [Chiefly South Midland and Southern U.S.] great in number or amount:
   a powerful lot of money.

• Middle English powarfull. See power, -ful 1350–1400

pow′er•ful•ly, adv. 
pow′er•ful•ness, n. 
Synonyms

• 1. forceful, strong.
  Powerful, mighty, potent suggest great force or strength.
  Powerful suggests capability of exerting great force or overcoming strong resistance:
  a powerful machine like a bulldozer.
  Mighty, now chiefly rhetorical, implies uncommon or overwhelming strength of power:
  a mighty army.
  Potent implies great natural or inherent power:
  a potent influence.
• 5. influential, convincing, forcible, cogent, effective.

Antonyms

• 1. weak.

Collins Concise English Dictionary © HarperCollins Publishers::

powerful / ˈpaʊəfʊl/ adjective

1. having great power, force, potency, or effect
2. extremely effective or efficient in action: a powerful drug, a powerful lens
3. large or great: a powerful amount of trouble

adverb

1. extremely; very: he ran powerful fast

ˈpowerfully adverb

ˈpowerfulness noun