n.someone who relieves a commander

Second in Command
Second in Command
Second in Command
Second-in-Command : Creating Leadership and Management Opportunities through Organizational Structures
General Nobile and the Airship Italia: No Second-In-Command
Second-in-command of Tulsa police force resigns after fatal shooting of unarmed black man
Don't get stuck as the second-in-command
School Board Narrows Chief List; Six Finalists for Superintendent Selected, Including District's Second-in-Command
Al Qaeda's Second-in-Command Applauds Democratic War Bill
Mass. Fund Hunts for Second-in-Command
Watergate & the Weather Underground: Former FBI Second-in-Command Mark Felt, Aka Watergate's "Deep Throat,"Was an Opponent of Both ...
FRA names new second-in-command
Reuters Second-in-Command Forced Out