The word "tentum" is spelled with a "t" and "u" combination that represents the Latin word "tentorium," meaning "tent" or "covering." It is pronounced as /ˈtɛntəm/ with emphasis on the first syllable. The "e" sound in the second syllable is short and followed by a nasal "n" sound. The final syllable is pronounced with the "uhm" sound spelled with "m." This spelling may seem perplexing to those unfamiliar with Latin, but it helps preserve the historical roots of the word.
Penis.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.