Where does “retrogressurus” come from?

retrogressurus (Latin) comes from Latin retrogradior, from Latin retrō, from Latin dūcere, from Proto-Italic doukō, from Proto-Indo-European déwketi, from Proto-Indo-European dewk- — to pull, to draw; to lead.

Definitions

Ancestry of “retrogressurus”, step by step

Step	Language	Word	Meaning
1	Latin	retrogradior	I go or step back or backwards, retrograde
2	Latin	retrō	back, backwards, behind
3	Latin	dūcere	—
4	Proto-Italic	doukō	lead
5	Proto-Indo-European	déwketi	—
6	Proto-Indo-European	dewk-	to pull, to draw; to lead

Every word from Proto-Indo-European dewk- →Every word from Proto-Indo-European déwketi →Every word from Proto-Italic doukō →