enervation
1. [ noun ] lack of vitality
Examples:

"an enervation of mind greater than any fatigue"

Related terms: weakness enervate
2. [ noun ] serious weakening and loss of energy
Synonyms: enfeeblement exhaustion debilitation
Related terms: weakening enfeeble
Similar spelling:   ennervation
  enervating
  enervate
  enervated
  enrapture
  enraptured