Where does “світлонепроникний” come from?

світлонепроникний (Ukrainian) comes from Ukrainian непроникни́й, from Ukrainian не-, from Ukrainian з-, from Ukrainian леті́ти, from Old East Slavic летѣти, from Proto-Slavic letěti, from Proto-Indo-European lēk- — string, twig, tendril; leg, the main muscle of...

світлонепроникний (Ukrainian): light-blocking, light-impermeable, lightproof, nontranslucent

Definitions

  1. light-blocking, light-impermeable, lightproof, nontranslucent

Ancestry of “світлонепроникний”, step by step

світлонепроникний traces back through two separate lines of ancestry.

via Ukrainian непроникни́й

StepLanguageWordMeaning
1Ukrainianнепроникни́йimpenetrable, impermeable, impervious, tight
2Ukrainianне-not; un-
3Ukrainianз-attached to imperfective verbs to form the perfective aspect
4Ukrainianлеті́тиto fly
5Old East Slavicлетѣти
6Proto-Slavicletětito fly
7Proto-Indo-Europeanlēk-string, twig, tendril; leg, the main muscle of...

via Ukrainian сві́тло

StepLanguageWordMeaning
1Ukrainianсві́тлоlight
2Proto-Slavic*světьlolight
Every word from Proto-Indo-European lēk-Every word from Ukrainian не-Every word from Proto-Slavic letěti