Where does “dreng” come from?

dreng (Danish) comes from Old Norse drengr, from Proto-Germanic drangijaz — stake; staff; crutch; support; man; servant.

dreng (Danish): boy, lad

Definitions

Step	Language	Word	Meaning
1	Old Norse	drengr	lad, youth, young man, in the sense of a warrior;...
2	Proto-Germanic	drangijaz	stake; staff; crutch; support; man; servant

dreng — Etymology, Origin & Word History | Etymology Explorer