Understeors or Understairs: How To spell?

The word Understeors is misspelled against Understairs, a noun meaning "The basement or cellar."

Word contains consecutive vowels 'AI' in between alphabets underst & rs is misspelled as 'EO'
Wrong Spelling:  underst-eo-rs 
Correct Spelling:  underst-ai-rs 
Find more incorrect spellings of Understairs to spell right way.

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