Where does “гъсталак” come from?

гъсталак (Bulgarian) comes from Bulgarian гъст, from Old Church Slavonic гѫстъ, from Proto-Slavic gǫstъ — dense.

Ancestry of “гъсталак”, step by step

StepLanguageWordMeaning
1Bulgarianгъстthick, dense
2Old Church Slavonicгѫстъ—
3Proto-Slavicgǫstъdense
Every word from Proto-Slavic gǫstъ →Every word from Old Church Slavonic гѫстъ →Every word from Bulgarian гъст →