physically weak, as from age or sickness; frail.

weak intellectually or morally

a feeble mind.

lacking in volume, loudness, brightness, distinctness, etc.

a feeble voice; feeble light.

lacking in force, strength, or effectiveness

feeble resistance; feeble arguments.

adjective

able , effective , hardy , healthy , hearty , powerful , solid , sound , strong

adjective

aged , ailing , chicken * , debilitated , decrepit , delicate , doddering , dopey * , effete , emasculated , enervated , enfeebled , etiolated , exhausted , failing , faint , flabby * , flat , fragile , frail , gentle , helpless , impotent , inadequate , incompetent , indecisive , ineffectual , inefficient , infirm , insubstantial , insufficient , lame , languid , low , out of gas , paltry , poor , powerless , puny , sapless , sickly , slight , strengthless , tame , thin , unconvincing , vitiated , weak , weakened , weakly , wimpy , woozy * , zero * , flimsy , unsound , unsubstantial , asthenic , disabled , doddering. weak , flaccid , impuissant , ineffective , inferior , insipid , invalid , languorous , pointless , senile