No. It is an adverb. It means "in that respect."
therein
He never returned to his home-town, and therein lies a mystery.
barren
The cast of Therein - 2012 includes: Yotum Almor Rebecca Doran as Juniper
The seven-letter word that contains 10 different words without rearranging any letters is "therein." The words that can be formed using the letters of "therein" are: the, there, herein, herein, here, there, ere, rein, in, and he.
2
Four.
16
26.2
1000
Therein
The word therein. They are: There I in the here her he rein ere herein and therein.