Parent, for example

• Nanny, for one
• One bringing up children behind the Queen
• Nervous horse, perhaps
• Frightened horse
• Parent or scared horse
• Terrified horse, at times
• Silver, for example, in the opening to TV's "The Lone Ranger"
• Parent, e.g.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Rearer \Rear"er\ (r[=e]r"[~e]r), n. One who, or that which, rears.