noun (n)

• a stable situation in which forces cancel one another(noun.state)

  Antonym:
  disequilibrium
  

  source: wordnet30
• a chemical reaction and its reverse proceed at equal rates(noun.process)

  Synonym:
  chemical equilibrium
  

  source: wordnet30
• equality of distribution(noun.shape)

  Synonym:
  balance, counterbalance, equipoise
  

  source: wordnet30
• a sensory system located in structures of the inner ear that registers the orientation of the head(noun.cognition)

  Synonym:
  labyrinthine sense, sense of balance, sense of equilibrium, vestibular sense
  

  source: wordnet30
• Equality of weight or force; an equipoise or a state of rest produced by the mutual counteraction of two or more forces.(noun)

  source: webster1913