An Etymological Dictionary of the German Language/Pilger
Pilger, m., and in an elevated antiquated style Pilgrim, ‘pilgrim,’ from MidHG. pilgrîn, bilegrîm (Pilger, from MidHG. pilgrî), m., OHG. piligrîm, m., ‘pilgrim,’ formed from MidLat. peregrînus. From OHG. is derived E. pilgrim. The change of Lat. r and n into HG. l and m is similar to that in Pflaume; the l in this word is found also in Rom.; comp. Fr. pélerin, Ital. pellegrino, ‘pilgrim’; in Italy, and espec. in Rome, the change of meaning; from ‘foreigner’ to ‘pilgrim’ was easily suggested. The word was borrowed by HG. in the 9th, and by E. in the 12th cent.