地ち下か核かく実じっ験けんMeaningsNoun1. underground nuclear testKanji used地ground下below核nucleus実real験verificationComposed of地ち下かunderground; below the ground; world of the dead; the grave; underground (activities, movement, etc.); secret; illegal; in hidingNoun核かく実じっ験けんnuclear (bomb) testNoun