ringer (n.)

• agent
• alternate
• alternative
• analogy
• backup
• bluff
• bluffer
• change
• changeling
• charlatan
• comparison
• copy
• counterfeit
• deputy
• double
• dummy
• equal
• equivalent
• ersatz
• exchange
• fake
• faker
• fill-in
• fraud
• ghost
• ghostwriter
• humbug
• imitation
• impersonator
• impostor
• makeshift
• malingerer
• metaphor
• metonymy
• mountebank
• personnel
• phony
• picture
• portrait
• poser
• poseur
• pretender
• proxy
• quack
• relief
• replacement
• representative
• reserves
• secondary
• sham
• shammer
• sign
• simulacrum
• spit
• stand-in
• sub
• substitute
• substitution
• succedaneum
• supplanter
• surrogate
• symbol
• synecdoche
• token
• understudy
• vicar
• vice-regent