An Etymological Dictionary of the German Language/Papst
Papst, Pabst, m., ‘pope,’ from MidHG. bâbes, and with an excrescent t (see Obst and Palast), bâbest; OHG. bâbes first occurs about 1000 A.D. (in Notker); from the equiv. Lat. pâpa. The initial and medial b in OHG. and MidHG. in contrast to Lat. p may be compared with bëch, balme, bapel, and their variants pëch, palme, papel, in MidHG. The s of the OHG. form bâbes (earlier *bâbas?) is both strange and difficult to explain; comp. OSlov. papežĭ, borrowed from it. This Latin Church word, which passed into G. at a late period, cannot be connected with ModGr. πάππας (comp. Pfaffe); most of the corresponding Rom. words have, however, no s (Ital. papa, Fr. pape). Yet OFr. has sometimes pape-s instead of pape, with an inorganic s in the nom. (comp. Pfau), for in OFr. numerous mascs. in a could take an s in the nom. (poetes from poeta, prophetes from propheta, hermites from eremita, homicides from homicida, &c.). In MidEuropean Ger. this form in s afterwards constituted the stem; besides OHG. bâbes comp. also Du. paus (from OLG. and ODu. pavos, recorded even in the 9th cent.). The LG. form seems to have passed in the 10th cent. to the south of Germany. OIc. páfe was probably formed under the influence of AS. pâpa (Lat. pâpa), E. pope. Moreover, MidLat. pâpa was a respectful term used in addressing bishops, and since Leo the Great a title of the Roman pope, and also since Hierocles the title of the patriarch of Alexandria. Gregory VII. decreed in 1075 the exclusive right of the Roman pontifex to the title papa. The fact that AS. has preserved the Lat. word in a purer form is explained by its having been borrowed at an earlier period.