proponent
noun
[ prəˈpəʊnənt ]
• a person who advocates a theory, proposal, or course of action.
• "a strong proponent of the free market and liberal trade policies"
Similar:
advocate,
supporter,
upholder,
exponent,
promoter,
adherent,
endorser,
champion,
defender,
backer,
subscriber,
patron,
espouser,
friend,
apostle,
apologist,
pleader,
proposer,
propounder,
spokesperson,
spokesman,
spokeswoman,
enthusiast,
propagandist,
Origin:
late 16th century: from Latin proponent- ‘putting forth’, from the verb proponere (see propound).