Rare words in the Old Bulgarian translation of Prophet Isaiah’s book

The subject of the research are the yet unregisrated in the Old Bulgarian language lexicographic referrences words or such words, just noted with an example in the same context of the book of Isaia with interpretations, based on manuscript F.I.461 from the National Library of Russia – St. Petersburg. The analysis of the hapax legomena and the rare words is performed in the composition of semanthic categories (groups) and lexis and wordforming paterns. The wordforming models of the terminative and rare words in IsF.I.461 are being analysed, in order to elucidate their connection with the lexis of the classic Old Bulgarian manuscripts and the indirect sources of Old Bulgarian language.