Where does “tenh₂-wó-s” come from?

tenh₂-wó-s (Proto-Balto-Slavic) comes from Proto-Indo-European ténh₂us, from Proto-Indo-European tenh₂-, from Proto-Indo-European ten- — to stretch, to extend.

Ancestry of “tenh₂-wó-s”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	ténh₂us	thin
2	Proto-Indo-European	tenh₂-	to stretch, to extend
3	Proto-Indo-European	ten-	to stretch, to extend

Every word from Proto-Indo-European ten- →Every word from Proto-Indo-European tenh₂- →Every word from Proto-Indo-European ténh₂us →