What does ° mean in Latin?

°, a symbol, means “denoting birth, born”.

°

denoting birth, born
De Luca Debes (°Stubbekøbing / Falster 1623 — †Thorshavn 28 IX 1675) vide vitam in Dansk Biografisk Leksikon, vol. V (Hauniae 1934), pp. 624–625.1996, Josephus Antonius Maria Carolus Ĳsewĳn, Ulfus Timmermann, “Specimen Latinitatis Faroensis”, in Humanistica Lovaniensia: Journal of Neo-Latin Studies, volume XLV, Lovanium: Leuven University Press, →ISBN, →ISSN, footnote 7 (on page 507):