From The Collaborative International Dictionary of English v.0.48 :
Forbiddance \For*bid"dance\, n. The act of forbidding; prohibition; command or edict against a thing. [Obs.] [1913 Webster] How hast thou yield to transgress The strict forbiddance. --Milton. [1913 Webster]From WordNet (r) 3.0 (2006) :
forbiddance n 1: an official prohibition or edict against something [syn: ban, banning, forbiddance, forbidding] 2: the action of prohibiting or inhibiting or forbidding (or an instance thereof); "they were restrained by a prohibition in their charter"; "a medical inhibition of alcoholic beverages"; "he ignored his parents' forbiddance" [syn: prohibition, inhibition, forbiddance]