— counteractant , adj. — counteracter, counteractor , n. — counteractingly , adv. — counteraction , n. — counteractive , adj. — counteractively , adv.
/kown'teuhr akt"/ , v.t.
to act in opposition to; frustrate by contrary action.
[ 1670-80; COUNTER- + ACT ]
Syn . neutralize, counterbalance, contravene, thwart.