What is the meaning of one?

noun

• The smallest whole number or a numeral representing this number.
  • usage: "he has the one but will need a two and three to go with it"; "they had lunch at one"
  • synonyms: 1, I, ace, single, unity
• A single person or thing.
  • usage: "he is the best one"; "this is the one I ordered"

adjective

• Used of a single unit or thing; not two or more.
  • usage: "`ane' is Scottish"
  • synonyms: 1, i, ane
• Having the indivisible character of a unit.
  • usage: "a unitary action"; "spoke with one voice"
  • synonyms: unitary
• Of the same kind or quality.
  • usage: "two animals of one species"
• Used informally as an intensifier.
  • usage: "that is one fine dog"
• Indefinite in time or position.
  • usage: "he will come one day"; "one place or another"
• Being a single entity made by combining separate components.
  • usage: "three chemicals combining into one solution"
• Eminent beyond or above comparison.
  • usage: "matchless beauty"; "the team's nonpareil center fielder"; "she's one girl in a million"; "the one and only Muhammad Ali"; "a peerless scholar"; "infamy unmatched in the Western world"; "wrote with unmatchable clarity"; "unrivaled mastery of her art"
  • synonyms: matchless, nonpareil, one and only, peerless, unmatched, unmatchable, unrivaled, unrivalled