oppositional (?.)
- adversary
- adversative
- adverse
- adversive
- alien
- antagonistic
- anti
- antipathetic
- antithetic
- antonymous
- at cross-purposes
- balancing
- breakaway
- clashing
- compensating
- competitive
- con
- conflicting
- confronting
- contradicting
- contradictory
- contradistinct
- contrapositive
- contrarious
- contrary
- contrasted
- converse
- counter
- counteractant
- counteracting
- counteractive
- counterbalancing
- counterpoised
- countervailing
- counterworking
- cranky
- cross
- crotchety
- dead against
- disaccordant
- discordant
- discrepant
- dissentient
- dissident
- enemy
- eyeball to eyeball
- fractious
- hostile
- inconsistent
- inimical
- inverse
- negative
- nonconformist
- noncooperative
- obstinate
- obverse
- opponent
- opposed
- opposing
- opposite
- oppositive
- oppugnant
- overthwart
- perverse
- reactionary
- recalcitrant
- refractory
- renitent
- repugnant
- resistant
- reverse
- revolutionary
- rival
- squared off
- uncooperative
- unfavorable
- unfriendly
- unpropitious