Where does “Sikora” come from?

Sikora (English) comes from Polish Sikora, from Proto-Slavic sykora, from Proto-Slavic sykati — to hiss.

Ancestry of “Sikora”, step by step

StepLanguageWordMeaning
1PolishSikorachickadee, tit, titmouse
2Proto-Slavicsykoratit (bird of the family Paridae)
3Proto-Slavicsykatito hiss
Every word from Proto-Slavic sykati →Every word from Proto-Slavic sykora →Every word from Polish Sikora →