Source : Webster's Revised Unabridged Dictionary (1913)

Cellulitis \Cel`lu*li"tis\, n. [NL., fr. L. cellula + -itis.]
   An inflammantion of the cellular or areolar tissue, esp. of
   that lying immediately beneath the skin.

Source : WordNet®

cellulitis
     n : an inflammation of body tissue (especially that below the
         skin) characterized by fever and swelling and redness and
         pain