Where does “gęściachny” come from?

gęściachny (Polish) comes from Polish -achny, from Polish -ch, from Old Polish -ch, from Proto-Slavic -xъ.

Ancestry of “gęściachny”, step by step

StepLanguageWordMeaning
1Polish-achnyforms augmentative masculine adjectives
2Polish-chAttached to truncated stems of common nouns to...
3Old Polish-chAttached to truncated stems of masculine given...
4Proto-Slavic-xъ—
Every word from Proto-Slavic -xъ →Every word from Polish -ch →Every word from Polish -achny →