Synonyms for Opposing (same or very similar meaning)
WordNet sense 1 (in opposition to (a policy or attitude etc.)):
opposed
WordNet sense 2 (not in favor of (an action or proposal etc.)):
anti
WordNet sense 3 (characterized by active hostility):
opponent
WordNet sense 4 (characterized by enmity or ill will):
hostile
From the ODE community, based on WordNet
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