Where does “contrascribendus” come from?

contrascribendus (Latin) comes from Latin contrascribo, from Latin scrībō, from Proto-Italic skreiβō, from Proto-Indo-European skreybʰ- — to write.

Definitions

Step	Language	Word	Meaning
1	Latin	contrascribo	I countersign
2	Latin	scrībō	—
3	Proto-Italic	skreiβō	to carve
4	Proto-Indo-European	skreybʰ-	to write

contrascribendus — Etymology, Origin & Word History | Etymology Explorer