Souterain or Souterrain: How To spell?
The word Souterain is misspelled against Souterrain, a noun meaning "A grotto or cavern under ground."
Souterrain has double "rr" is mispronounced as "r"Remember double 'RR' in between the strings soute & ain which should not be misspelled with single 'R'
Wrong Spelling:  soute-r-ain  Correct Spelling:  soute-rr-ain 
Check more misspelled words of Souterrain to spell it correct.