LAS'SITUDE, noun [Latin lassitudo, from lassus, and this from laxus, laxo, to relax.]

1. Weakness; dullness; heaviness; weariness; languor of body or mind, proceeding from exhaustion of strength by excessive labor or action, or other means.

2. Among physicians, lassitude is a morbid sensation or languor which often precedes disease, in which case it proceeds from an impaired or diseased action of the organs.