antagonize (v.)

• aggravate
• alienate
• battle
• buck
• buffet
• clash
• collide
• combat
• conflict
• confute
• contest
• contradict
• contravene
• counter
• counteract
• counterattack
• counterpose
• countervail
• cross
• embitter
• envenom
• estrange
• exacerbate
• fight
• infuriate
• madden
• oppose
• oppugn
• provoke
• resist
• rival