The spelling of "sangapenum" may seem confusing; however, it can be easily explained using IPA phonetic transcription. The word is pronounced as /sæŋəˈpɛnəm/ in IPA, with the stress on the second syllable. The "ng" sound is followed by a vowel sound, represented by "a" and "e" in the spelling. The ending "-enum" is pronounced with a slight stress on the "e" sound, written as "ɛ" in IPA. Therefore, "sangapenum" can be pronounced as "sang-uh-PEH-num."
a variety of gum
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.