standbyguard
nounUK /ˈstændbaɪɡɑːd/
US /ˈstændbaɪɡɑːrd/
A standbyguard is a helper who waits and gets ready to keep someone safe.
The standbyguard stood by the door, ready to help if anyone needed him.
OTHER MEANINGS
2. A person who takes over guarding when the main guard rests.
When the night guard got tired, the standbyguard took his place.
3. A device that stays ready to protect something if the main one fails.
The standbyguard alarm turned on when the power went out.
4. A player who waits on the bench to defend the team if needed.
The coach sent in the standbyguard during the last minute of the game.