noun (n)

• an abnormal protuberance or localized enlargement(noun.state)

  Synonym:
  lump, puffiness
  

  source: wordnet30
• something that bulges out or is protuberant or projects from its surroundings(noun.shape)

  Synonym:
  bulge, bump, excrescence, extrusion, gibbosity, gibbousness, hump, jut, prominence, protrusion, protuberance
  

  source: wordnet30
• the increase in volume of certain substances when they are heated (often accompanied by release of water)(noun.process)

  Synonym:
  intumescence, intumescency
  

  source: wordnet30
• The act of that which swells; as, the swelling of rivers in spring; the swelling of the breast with pride.(noun)

  source: webster1913