Interdict  —n. 1 authoritative prohibition. 2 rc ch. Sentence debarring a person, or esp. A place, from ecclesiastical functions and privileges. —v. 1 prohibit (an action). 2 forbid the use of. 3 (usu. Foll. By from + verbal noun) restrain (a person). 4 (usu. Foll. By to) forbid (a thing) to a person.  interdiction n. Interdictory adj. [latin dico say]