noun (n)

• a calm, lengthy, intent consideration(noun.cognition)

  Synonym:
  contemplation, musing, reflection, reflexion, thoughtfulness
  

  source: wordnet30
• (of ruminants) chewing (the cud)(noun.act)

  Example:
  Ruminants have remarkable powers of rumination.
  

  source: wordnet30
• regurgitation of small amounts of food; seen in some infants after feeding(noun.act)

  source: wordnet30
• The act or process of ruminating, or chewing the cud; the habit of chewing the cud.(noun)

  source: webster1913