Synonyms for Opposer:

n.

resist, support, Oppositionist. opponent (noun)
rival, disputant, Archenemy, antagonist, opposite, attacker, foe, competitor, enemy, adversary, opponent, foil, Oppositionist, combatant, assailant, contestant, assaulter, resister, villain.
opposer (noun)
antagonist, resister, opponent, adversary.

Other synonyms:

Oppositionist. Other relevant words:
resister, Oppositionist, support, resist.

Usage examples for opposer

  1. Mr. C. declared himself thoroughly convinced of the propriety of immediate emancipation; though he was once a violent opposer of abolition. – The Anti-Slavery Examiner, Omnibus by American Anti-Slavery Society
  2. She knew the poor woman was trying to be kind and merciful and sympathetic, but she also knew that what she had just said had rendered Noel's mother the foe and opposer of this marriage, instead of its friend. – A Beautiful Alien by Julia Magruder