It is currently used to treat leprosy.Origin of thalidomide (ph)thal(ic acid) + (im)id(e) + (i)mide. thalidomideNoun (uncountable)(pharmacology) (RS)-2-(2,6-dioxopiperidin-3-yl)-1H-isoindole-1,3(2H)dione ??? C13H10N2O4 ??? A drug that was sold during the late 1950s and 1960s as a sleeping aid, and to pregnant women as an antiemetic to combat morning sickness and other symptoms, but was withdrawn