Where does “tos” come from?

tos (Old Occitan) comes from Latin tussis, from Proto-Italic tussis, from Proto-Indo-European tud-ti-s, from Proto-Indo-European (s)tewd-, from Proto-Indo-European stew- — to praise, laud.

Ancestry of “tos”, step by step

Step	Language	Word	Meaning
1	Latin	tussis	cough
2	Proto-Italic	tussis	—
3	Proto-Indo-European	tud-ti-s	cough
4	Proto-Indo-European	(s)tewd-	to push, to hit
5	Proto-Indo-European	stew-	to praise, laud

Words derived from “tos”

Every word from Proto-Indo-European stew- →Every word from Proto-Indo-European (s)tewd- →Every word from Proto-Indo-European tud-ti-s →