Where does “graduō” come from?

graduō (Latin) comes from Latin gradus, from Proto-Italic graðus, from Proto-Indo-European gʰradʰ-.

Ancestry of “graduō”, step by step

Step	Language	Word	Meaning
1	Latin	gradus	a step, pace; a stage, degree; a rank
2	Proto-Italic	graðus	—
3	Proto-Indo-European	gʰradʰ-	—