One word Substitution: A person who insists on something?

One word Substitution: A person who insists on something?

Explanation
  • A stickler is a person who insists on something, especially a rule or a detail, and is unwilling to compromise or be flexible.
  • Boaster: A person who talks with pride about their achievements or possessions.
  • Disciplinarian: A person who believes in and enforces strict rules and punishments.
  • Instantaneous: Happening or done immediately, without delay.