What is the meaning of past?

noun

• The time that has elapsed.
  • usage: "forget the past"
  • synonyms: past times, yesteryear
• A earlier period in someone's life (especially one that they have reason to keep secret. )
  • usage: "reporters dug into the candidate's past"
• A verb tense that expresses actions or states in the past.
  • synonyms: past tense

adjective

• Earlier than the present time; no longer current.
  • usage: "time past"; "his youth is past"; "this past Thursday"; "the past year"
• Of a person who has held and relinquished a position or office.
  • usage: "a retiring member of the board"
  • synonyms: preceding, retiring

adverb

• So as to pass a given point.
  • usage: "every hour a train goes past"
  • synonyms: by