a. 反对的, 反作用的, 抵抗的

n. 中和剂, 对抗力, 中和力

[ adj ]
opposing or neutralizing or mitigating an effect by contrary action
<adj.all>

Counteractive \Coun`ter*act"ive\ (-?kt"?v), a.
Tending to counteract.


Counteractive \Coun`ter*act"ive\, n.
One who, or that which, counteracts.