Thereun or Therein: How To spell?
The word Thereun 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 'EU'Wrong Spelling:  ther-eu-n  Correct Spelling:  ther-ei-n 
Check more misspelled words of Therein to spell it correct.