merde n.

also merd, "dung, excrement," late 15c., from Old French merde "feces, excrement, dirt" (13c.), from Latin merda "dung, ordure, excrement." De Vaan compares Lithuanian smirdėti "to stink," Latvian smards "smell, odor," dialectal Russian smorod, Ukrainian smorid, genitive smorodu "stink," from a PIE *smerdh- "stench." Merd was naturalized in English through 17c., but subsequently lost and since mid-19c. (and especially since World War I) it has been generally treated as a French word when used in English.