Lethein or Lethean: How To spell?
The word Lethein is misspelled against Lethean, an adjective meaning "pertaining to Lethe; resembling in effect the water Lethe."
Lethean has vowels 'ea' together mispronounced as 'ei'Word contains consecutive vowels 'EA' in between alphabets leth & n is misspelled as 'EI'
Wrong Spelling:  leth-ei-n  Correct Spelling:  leth-ea-n 
Find more wrongly spelled words of Lethean to spell it well.