Please do not (do)

緑泥石: chlorite (mineral)

でんぐり返り: the act of turning something over or turning something upside-down; a somersault (either forwards or backwards)

でんぐり返し: to somersault

でんぐり返す: to turn something over, to turn something upside-down; to make someone or something do a somersault (either forwards or backwards)

でんぐり返る: to turn over, to turn upside-down; to do a somersault (either forwards or backwards); to be head over heels, to be in disarray, to be very confused

でんぐり返し: the act of turning something over or turning something upside-down; a somersault (either forwards or backwards)

でんぐり返り: to somersault

(idiomatic) to be relieved

polite form of - ではない (de wa nai, “not, is not”)