Retonal or Retainal: How To spell?
The word Retonal is misspelled against Retainal, a noun meaning "The act of retaining; retention."
Word contains consecutive vowels 'AI' in between alphabets ret & nal is misspelled as 'O'Wrong Spelling:  ret-o-nal  Correct Spelling:  ret-ai-nal 
Find more incorrect spellings of Retainal to spell right way.