A watchman, sentinel or bodyguard for a king or ruler. The word is also used metaphorically.
Bodyguards for kings
See also
pp 1Ch 11:25
Guards at the tomb of Jesus Christ
Other examples of human guards
pp Jer 39:9
Angelic guards
The LORD guards his people himself
pp Ps 18:30
Figurative references to guarding
Guarding one's conduct
Jesus Christ warns his disciples against the Pharisees and Sadducees:
Guarding one's tongue
Christians are to guard the gospel
Church leaders are to guard those in their care