stone dead
From Longman Dictionary of Contemporary Englishstone deadˌstone ˈdead adjective 1 DEADused to emphasize that a person or animal is dead2 → kill something stone deadExamples from the Corpusstone dead• Many of the Witch King's coven fell stone dead.• The face was frozen now, and the rest of the body was stone dead.• His interest in humanity now was stone dead, and probably had been for some time.