I. hwer-ˈin, wer-, (ˌ)(h)wər- adverb
Date: 13th century
: in what : in what particular or respect
wherein was I wrong
II. conjunction
Date: 14th century
1.
a. : in which : where
the city wherein he lives
b. : during which
2. : in what way : how
showed me wherein I was wrong