All powerful antonyms

adj powerful

• ineffective — not effective; not producing results; ineffectual: ineffective efforts; ineffective remedies.
• insignificant — unimportant, trifling, or petty: Omit the insignificant details.
• unimportant — of much or great significance or consequence: an important event in world history.
• impotent — not potent; lacking power or ability.
• incapable — not capable.
• ineffectual — not effectual; without satisfactory or decisive effect: an ineffectual remedy.
• inactive — not active: an inactive volcano.
• idle — not working or active; unemployed; doing nothing: idle workers.
• lethargic — of, relating to, or affected with lethargy; drowsy; sluggish; apathetic.
• unable — lacking the necessary power, competence, etc., to accomplish some specified act: He was unable to swim.
• weak — not strong; liable to yield, break, or collapse under pressure or strain; fragile; frail: a weak fortress; a weak spot in armor.