The spelling of the word "Periecians" can be tricky for non-native English speakers. According to the International Phonetic Alphabet (IPA), it is pronounced as /pɛrɪˈiːʃənz/. The first syllable is pronounced as "per" with a short "e" sound, followed by "i" with a long "e" sound. The ending is pronounced as "shians" with a silent "c". The word is derived from the Greek word "peri" which means "around" and refers to people living around a particular area.
See under perioeci.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.