expounder

1 a person who actively supports or favors a cause <an articulate expounder of the liberal position on the issue> Synonyms advocate, advocator, apostle, backer, booster, champion, exponent, espouser, friend, gospeler (or gospeller), herald, hierophant, high priest, paladin, promoter, proponent, protagonist, supporter, true believer, tub-thumper, white knightRelated Words loyalist, partisan (also partizan), stalwart; adherent, cohort, disciple, follower; interpreter; applauder, cheerleader, encourager, fellow travelerNear Antonyms enemy, foe, rival; belittler, critic, faultfinderAntonyms adversary, antagonist, opponent

2 one who brings an art or science to full realization <one of the early expounders of abstract expressionism> Synonyms exponent, guru, high priest, interpreter, practitionerRelated Words dean, doyen, grand old man; ideologue (also idealogue), philosopher, theorist; advocate, apostle, backer, booster, champion, promoter, proponent, supporter