{v. phr.} To try in every way; miss no chance; do everything possible. - Usually used in the negative. * /The police will leave no stone unturned in their search for the bank robbers./ Compare: ALL OUT, BEND HEAVEN AND EARTH, FINE-TOOTH COMB.
LEAVE NO STONE UNTURNED
Meaning of LEAVE NO STONE UNTURNED in English
Slang English vocab. Английский сленговый словарь. 2012