Is it ensure, insure, or assure?
"to burn superficially or slightly, but so as to change the color or injure the texture," early 14c., perhaps an alteration of scorrcnenn "make dry, parch" (c.1200), of obscure origin, perhaps from Old Norse skorpna "to be shriveled," cognate with Old English scrimman "to shrink, dry up." Or perhaps from Old French escorchier "to strip off the skin," from Vulgar Latin excorticare "to flay," from ex- (see ex-) + Latin cortex (genitive corticis) "cork;" but OED finds this not likely. Scorched earth military strategy is 1937, translation of Chinese jiaotu, used against the Japanese in a bid to stem their advance into China.
symptom of plant disease in which tissue is "burned" because of unfavourable conditions or infection by bacteria or fungi. Unfavourable conditions include hot, dry wind in full sun, an imbalance of soil nutrients, altered water table or soil grade, deep planting, compacted shallow soil, paved surface over roots, salt drift near the ocean, low temperatures, air pollutants, and girdling roots. Scorch is common as dead areas along or between the veins and margins of leaves. Control involves correcting the causative environmental condition: growing plants in fertile soil in a protected location and maintaining vigour by proper watering, fertilizing, pruning, and mulching. See also sunscald.