Where does “strēnuus” come from?

strēnuus (Latin) comes from Proto-Indo-European (s)treg- — rigid, stiff; to be stiff, rigid, strong.

Ancestry of “strēnuus”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	(s)treg-	rigid, stiff; to be stiff, rigid, strong

strēnuus — Etymology, Origin & Word History | Etymology Explorer