sub (n.)
- agent
- alternate
- alternative
- analogy
- backup
- change
- changeling
- collateral
- common
- comparison
- copy
- counterfeit
- dependent
- deputy
- double
- dummy
- equal
- equivalent
- ersatz
- exchange
- fake
- fill-in
- ghost
- ghostwriter
- imitation
- inferior
- junior
- less
- low
- lower
- makeshift
- metaphor
- metonymy
- minor
- ordinary
- personnel
- phony
- pigboat
- proxy
- relief
- replace
- replacement
- representative
- reserves
- ringer
- secondary
- sign
- spell
- stand-in
- subaltern
- subject
- submarine
- submersible
- subordinate
- substitute
- substitution
- succedaneum
- supplanter
- surrogate
- symbol
- synecdoche
- token
- tributary
- under
- understudy
- vicar
- vice-regent
