countermove noun 1verb 1forms 3 noun1 •A move in opposition or response to a preceding move.There are countermeasures to deceptive jamming, too, just as there are ECCCM to ECCM, all the way to infinity. It’s a giant chess game out there, moves to countermoves, and it never stops. — 1983 verb1 •To move in opposition or in retaliation. formscountermoved · countermoving · countermoves