English to English

noun (n)

• a painful and involuntary muscular contraction(noun.state)

  Synonym:
  cramp, muscle spasm
  

  source: wordnet30
• (pathology) sudden constriction of a hollow organ (as a blood vessel)(noun.act)

  source: wordnet30
• An involuntary and unnatural contraction of one or more muscles or muscular fibers.(noun)

  source: webster1913