Backstur or Backstair: How To spell?
The word Backstur is misspelled against Backstair, an adjective meaning "Private; indirect; secret; intriguing; -- as if finding access by the back stairs."
Word contains consecutive vowels 'AI' in between alphabets backst & r is misspelled as 'U'Wrong Spelling:  backst-u-r  Correct Spelling:  backst-ai-r 
Check more misspelled words of Backstair to spell it correct.