noun (n)

• a relative position or degree of value in a graded group(noun.state)

  Synonym:
  grade, level
  

  source: wordnet30
• any one of two or more competitors who tie one another(noun.person)

  source: wordnet30
• a worker who ties something(noun.person)

  Synonym:
  tier up
  

  source: wordnet30
• something that is used for tying(noun.artifact)

  Example:
  The sail is fastened to the yard with tiers.
  

  source: wordnet30
• one of two or more layers one atop another(noun.artifact)

  Example:
  Tier upon tier of huge casks.
  A three-tier wedding cake.
  

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

  source: webster1913
• A chold's apron covering the upper part of the body, and tied with tape or cord; a pinafore.(noun)

  source: webster1913
• A row or rank, especially one of two or more rows placed one above, or higher than, another; as, a tier of seats in a theater.(noun)

  source: webster1913