Earlier this year, just as Covid vaccines were rolling out, I learned that the etymologies of "Cingular" and "Shingles" (don't ask!) are both the Latin word cingula ("a girdle, band, belt, or strip of cloth"), as a frequency bandwidth or a stripe of blisters. It's also a cinch, to pick which definition applies to the phone carrier!
https://www.etymonline.com/word/shingles