Where does “lichy” come from?

lichy (Old Polish) comes from Proto-Slavic lixъ, from Proto-Indo-European leykʷ- — to leave.

Ancestry of “lichy”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	lixъ	remaining, unnecessary, superfluous, bad
2	Proto-Indo-European	leykʷ-	to leave

lichy — Etymology, Origin & Word History | Etymology Explorer