Dictionary:

designation

  (dĕz'ĭg-nā'shən)

1. The act of designating; a marking or pointing out.
2. Nomination or appointment.
3. A distinguishing name or title.

noun

1. The act of appointing to an office or position: appointment, nomination. See choice.
2. The word or words by which one is called and identified: appellation, appellative, cognomen, denomination, epithet, name, nickname, style, tag, title. Slang handle, moniker. See specific/general, words.

The noun has 3 meanings:

Meaning #1: identifying word or words by which someone or something is called and classified or distinguished from others
  Synonyms: appellation, denomination, appellative

Meaning #2: the act of putting a person into a non-elective position
  Synonyms: appointment, assignment, naming

Meaning #3: the act of designating or identifying something
  Synonym: identification