Vousoir or Voussoir: How To spell?
The word Vousoir is misspelled against Voussoir, a noun meaning "One of the wedgelike stones of which an arch is composed."
Voussoir has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings vou & oir which should not be misspelled with single 'S'
Wrong Spelling:  vou-s-oir  Correct Spelling:  vou-ss-oir 
Check more misspelled words of Voussoir to spell it correct.