Word Origin & History
c.1200, perhaps from O.N. skorpna "to be shriveled," cognate with O.E. scrimman "to shrink, dry up." Or perhaps from O.Fr. escorchier "to strip off the skin," from V.L. excorticare "to flay," from ex- + L. cortex (gen. corticis) "cork;" but OED finds this not likely. Scorcher "very hot day" first attested
1874. Scorched earth military strategy is 1937, translation of Chinese jiaotu, used against the Japanese in their advance into China.