pursuivant

/ˈpɜː.sɪ.vənt/

A follower

A functionary of lower rank than a herald, but discharging similar duties; called also pursuivant at arms; an attendant of the heralds, e.g. in the College of Arms.

A Grand Lodge Officer who guards the inner door during a meeting of the Grand Lodge

A royal messenger, one with the authority to execute warrants.

(law enforcement, by extension) A warrant officer.