Should be pronounced /ˈt͡siː.li̯ɔks/ (TSEEL-yawks, TSEE-lee-awks).
From what I could gather from the preview of
Wilfried Seibickes "Historisches deutsches Vornamenbuch" on Google Books it appears to be a version of
Cyriacus. I can't read the full article, though.
You could ask the philological department of the University of Leipzig.
https://www.philol.uni-leipzig.de/namenberatungsstelleThis message was edited 3/28/2025, 1:14 PM