Definitions of wherein:

• adverb:   in what

  Example: "Wherein consists this matter?"

• adverb:   in which; where

  Example: "The particular state wherein you reside"

• adverb:   in the course or during which

  Example: "A period wherein he did not work"

• adverb:   in regard to which

  Example: "A case wherein he took an active part"