כַּחֲשָׁא, (preced.) reduction, deterioration. B. Kam. 59ᵃ כַּחַשׁ גופנא the weakening of the vine (by allowing the grapes to remain on it until they are ripe). B. Mets. 101ᵇ משום כ׳ דארעא because he exhausted the soil by planting trees. Ib. 104ᵇ מנכי ליה כ׳ דארעא he must allow him a reduction of his rent in consideration of the lesser exhaustion of the soil (by having planted wheat in place of poppy).