c. 1600, "having the power of establishing," also "elemental, essential," from Medieval Latin *constitutivus, from constitut-, past-participle stem of constituere "to cause to stand, set up, fix, place, establish, set in order," from assimilated form of com-, here probably an intensive prefix (see com-), + statuere "to set," from PIE root *sta- "to stand, make or be firm." Related: Constitutively.
