Source : Webster's Revised Unabridged Dictionary (1913)

Countermove \Coun`ter*move"\ (koun`t?r-m??v"), v. t. & i.
   To move in a contrary direction to.

Countermove \Coun"ter*move`\ (-m??v`), n. Countermovement
\Coun"ter*move`ment\ (-ment).
   A movement in opposition to another.

Source : WordNet®

countermove
     n : an attack by a defending force against an attacking enemy
         force in order to regain lost ground or cut off enemy
         advance units etc. [syn: {counterattack}]