What is the meaning of classify?

verb

• Arrange or order by classes or categories.
  • usage: "How would you classify these pottery shards-are they prehistoric"
  • synonyms: class, sort, assort, sort out, separate
• Declare unavailable, as for security reasons.
  • usage: "Classify these documents"
• Assign to a class or kind.
  • usage: "How should algae be classified"; "People argue about how to relegate certain mushrooms"
  • synonyms: relegate