Plonness or Plainness: How To spell?

The word Plonness is misspelled against Plainness, a noun meaning "The quality or state of being plain."

Word contains consecutive vowels 'AI' in between alphabets pl & nness is misspelled as 'O'
Wrong Spelling:  pl-o-nness 
Correct Spelling:  pl-ai-nness 
Find more incorrect spellings of Plainness to spell right way.

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