Where does “горнятко” come from?

горнятко (Ukrainian) comes from Ukrainian -ко, from Proto-Slavic -ьko.

Ancestry of “горнятко”, step by step

StepLanguageWordMeaning
1Ukrainian-коCreates diminutives of normally neuter nouns and adverbs, normally having a colloquial register
2Proto-Slavic-ьko—
Every word from Proto-Slavic -ьko →Every word from Ukrainian -ко →
горнятко — Etymology, Origin & Word History | Etymology Explorer