any official who calls for silence
• (n.) One appointed to keep silence and order in court; also, one sworn not to divulge secrets of state.
Si·len'ti·a·ry (si*lĕn'shĭ*a*rȳ) noun [ Latin silentiarius : confer French silenciaire . See Silence .] One appointed to keep silence and order in court; also, one sworn not to divulge secrets of state. 
silentiary 1. One appointed to keep silence and order in court. 2. Someone who is sworn not to divulge secrets of state.