Therien or Therein: How To spell?
The word Therien is misspelled against Therein, an adverb meaning "In that or this place, time, or thing; in that particular or respect."
Word contains consecutive vowels 'EI' in between alphabets ther & n is misspelled as 'IE'Wrong Spelling:  ther-ie-n  Correct Spelling:  ther-ei-n 
Find more wrongly spelled words of Therein to spell it well.