Definition of King at Arms in English:

King at Arms

Pronunciation /ˌkɪŋ ət ˈɑːmz/

noun

  • (The title of) a herald who grants the right to wear or display arms; = "King of Arms".

    King at Arms and King of Arms are both well-attested, but the latter has now established itself as the more usual designation of any herald who holds such an office.

Origin

Mid 16th century; earliest use found in Hall's Vnion. From king+ at + arms, after post-classical Latin rex ad arma.