noun (n)

• a relaxed comfortable feeling(noun.feeling)

  Synonym:
  dreaminess
  

  source: wordnet30
• a feeling of lack of interest or energy(noun.feeling)

  Synonym:
  lassitude, listlessness
  

  source: wordnet30
• inactivity; showing an unusual lack of energy(noun.attribute)

  Synonym:
  flatness, lethargy, phlegm, sluggishness
  

  source: wordnet30
• A state of the body or mind which is caused by exhaustion of strength and characterized by a languid feeling; feebleness; lassitude; laxity.(noun)

  source: webster1913