noun

Abnormal physical weakness or lack of energy.

the asthenia of chronic respiratory disease

lethargy,inertia,listlessness,lack of energy,lifelessness,inactivity,inaction,dormancy,slowness,languor,languidness,torpor,torpidity,dullness,heaviness,apathy,passivity,weariness,tiredness,lassitude,fatigue,sleepiness,drowsiness,enervation,somnolence,laziness,idleness,indolence,sloth,slothfulness