noun (n)

• any artifact that makes a squeaking sound when used(noun.artifact)

  Example:
  Those sneakers are squeakers.
  Which hinge is the squeaker?.
  

  source: wordnet30
• something achieved (or escaped) by a narrow margin(noun.act)

  Synonym:
  close call, close shave, narrow escape, squeak
  

  source: wordnet30
• One who, or that which, squeaks.(noun)

  source: webster1913