Where does “dopukać” come from?

dopukać (Polish) comes from Polish do-, from Old Polish do-, from Proto-Slavic do-.

Ancestry of “dopukać”, step by step

Step	Language	Word	Meaning
1	Polish	do-	further, additionally; completing something...
2	Old Polish	do-	appended to verbs to indicate completion
3	Proto-Slavic	do-	—