ineffectual (adj.)

• abortive
• acarpous
• aimless
• arid
• barren
• bootless
• borne
• celibate
• childless
• counterproductive
• desolate
• drained
• dried-up
• dry
• effete
• emasculate
• empty
• etiolated
• exhausted
• failing
• fallow
• fatuous
• feckless
• forceless
• fruitless
• futile
• gaunt
• gelded
• impotent
• inadequate
• inane
• incapable
• incompetent
• ineffective
• inefficacious
• inefficient
• infertile
• inoperative
• invalid
• invertebrate
• jejune
• lame
• leached
• lightweight
• limited
• maladjusted
• manque
• mean
• meaningless
• menopausal
• narrow
• no-account
• nonproductive
• nugatory
• paltry
• pointless
• powerless
• purposeless
• set
• small
• spineless
• sterile
• stillborn
• superfluous
• unable
• unadapted
• unadjusted
• unavailable
• unavailing
• uncultivated
• unequipped
• unfertile
• unfit
• unfortunate
• unfruitful
• unplowed
• unproductive
• unqualified
• unsown
• unsuccessful
• untilled
• useless
• vain
• virgin
• waste
• wasted
• weak