Improvement. Amending, bettering, amelioration, amendment, progress, efficiency, proficiency, advancement, use, betterment; increase, correction.
Ant. Degeneracy, retrogradation, degeneration, debasement, deterioration, retrogression.
Impudence. Assurance, boldness, impertinence, pertness, rudeness, sauciness, effrontery, forwardness, incivility, insolence, presumption, officiousness, intrusiveness.
Ant. Bashfulness, humility, diffidence, meekness, lowliness, modesty, submissiveness; coyness, obsequiousness, subserviency, abasement.
Impugn. Attack, assail, contradict, oppose, resist, gainsay, controvert, deny, blame.
Ant. Declare, state, allege, approve, commend, defend, repel; propose, propound, confront, face.
Impulse. Thrust, push, impetus; passion, instinct, proclivity, inclination, appetite; motive, influence, incitement, instigation, incentive, force, sudden thought.
Ant. Deliberation, premeditation, rebuff, repulse.
Impulsive. Propulsive, impelling, moving; hot, quick, rash, hasty, passionate; wayward, impressible.
Ant. Discreet, hesitating, reluctant, timid, calculating, wary, cautious.