most ineffectual

abortive anticlimactic barren bootless defeasible feckless feeble forceless fruitless futile idle impotent inadequate incompetent indecisive inefficacious inefficient inept inferior innocuous inoperative invertebrate lame limited neutralized nugatory null null and void paltry powerless spineless unable unavailing unfruitful unproductive unprofitable unsuccessful vain void withered worthless

competent effective effectual efficient powerful strong useful

futile impotent inadequate ineffective inefficient insufficient unproductive

hopeless idle unable unavailing vain weak

able adequate capable competent enough productive sufficient

effective effectual