This is silver and gilt badge which is either Turkish/Egyptian from the WW1 period which recently sold on ebay. Posting the pics for the record and future reference.
I looked at at least a hundred photos of Egyptian & Turkish officers on the internet but could not find a single one showing someone with this badge, so would like a positive identification.
Flag of the Khedivate of Egypt (1881–1914) and the Sultanate of Egypt (1914–1922) feature three crescents and stars, so this could be Egyptian
Suggested meanings differ. Some scholars note that the three stars and crescents were symbolic of Ottoman victories across the continents of Asia, Africa, and Europe. Others maintain that the prevalence of three connotes Muhammed Ali’s sovereignty over Egypt, Sudan and al-Hegaz. The crescent is assumed from Islamic iconography, and remains a refernce to Islam’s use of the lunar calendar.
The flag was still used after the Ottoman withdrawal from Egyptian affairs in 1914; from then, Egypt was considered a sultanate and a British
protectorate.
https://egyptianstreets.com/2022/02/...-of-symbolism/