Related Clues:

• Finger-pointer
• Whistle-blower
• Snitch
• Tattletale
• Cooperative witness, maybe
• Stool pigeon
• New parent, e.g.
• One who assigns an identifying word
• Picker
• Moniker creator
• Title giver
• Parent, after birth
• One who makes appointments?
• Christener, e.g.
• Identifier