Where does “Jõulusaar” come from?

Jõulusaar (Estonian) comes from Estonian Saar, from Proto-Finnic sarni, from Polish Sarna, from Proto-Slavic sьrna, from Proto-Balto-Slavic śírˀnāˀ, from Proto-Indo-European ḱr̥h₂-néh₂, from Proto-Indo-European ḱerh₂- — head, top; horn.

Ancestry of “Jõulusaar”, step by step

Jõulusaar traces back through two separate lines of ancestry.

via Estonian Saar

StepLanguageWordMeaning
1EstonianSaar
2Proto-Finnicsarniash tree
3PolishSarnaroe deer
4Proto-Slavicsьrnaroe; chamois
5Proto-Balto-Slavicśírˀnāˀhorn
6Proto-Indo-Europeanḱr̥h₂-néh₂
7Proto-Indo-Europeanḱerh₂-head, top; horn

via Estonian jõulud

StepLanguageWordMeaning
1EstonianjõuludChristmas
Every word from Proto-Indo-European ḱerh₂-Every word from Proto-Indo-European ḱr̥h₂-néh₂Every word from Proto-Balto-Slavic śírˀnāˀ