Definition of custos sigilli in English:

custos sigilli

noun

rare, historical
  • In England: (the title of) an officer of state having custody of the Great Seal; = "(Lord) Keeper of the Great Seal".

Origin

Late 16th century. Shortened from post-classical Latin custos sigilli regis keeper of the king's seal from classical Latin custos + sigillī, genitive of sigillum + rēgis, genitive of rēx.

Pronunciation

custos sigilli

/ˌkʌstɒs sɪˈɡɪli//ˌkʌstɒs sɪˈdʒɪlʌɪ/