noun:
languor,
vapidity,
limpness,
lethargy,
pallidness,
tediousness,
apathy,
lifelessness,
inactivity,
dullness,
tedium,
languidness,
listlessness,
spiritlessness,
sleepiness,
indolence,
anemia,
torpidity,
impassivity,
weariness,
torpor,
laziness,
vapidness,
sluggishness.