MANUMISSION, contracts. The agreement by which the owner or master of a slave sets him free and at liberty; the written instrument which contains this agreement is also called a manumission. 2. In the civil law it was different from emancipation, which, properly speaking, was applied to the liberation of children from paternal power. Inst. liv. 1, t. 5 & 12; Co. Litt. 137, a; Dane's Ab. h.t.