noun (n)

• the parity of even numbers (divisible by two)(noun.linkdef)

  source: wordnet30
• a quality of uniformity and lack of variation(noun.attribute)

  Synonym:
  invariability
  Antonym:
  unevenness, variability
  

  source: wordnet30
• the quality of being balanced(noun.attribute)

  Antonym:
  unevenness
  

  source: wordnet30
• The state of being ven, level, or disturbed; smoothness; horizontal position; uniformity; impartiality; calmness; equanimity; appropriate place or level; as, evenness of surface, of a fluid at rest, of motion, of dealings, of temper, of condition.(noun)

  source: webster1913