Where does “rozsdák” come from?

rozsdák (Hungarian) comes from Hungarian rozsda, from Bulgarian ръжда, from Proto-Slavic rъďa, from Proto-Slavic rudъ, from Proto-Balto-Slavic roudos, from Proto-Indo-European h₁rowdʰ-o-, from Proto-Indo-European h₁rewdʰ- — red.

Ancestry of “rozsdák”, step by step

StepLanguageWordMeaning
1Hungarianrozsdarust
2Bulgarianръждаrust
3Proto-Slavicrъďarust
4Proto-Slavicrudъred, blood red, reddish; ginger; brown
5Proto-Balto-Slavicroudos—
6Proto-Indo-Europeanh₁rowdʰ-o-—
7Proto-Indo-Europeanh₁rewdʰ-red
Every word from Proto-Indo-European h₁rewdʰ- →Every word from Proto-Indo-European h₁rowdʰ-o- →Every word from Proto-Balto-Slavic roudos →