Fisilingual or Fissilingual: How To spell?
The word Fisilingual is misspelled against Fissilingual, an adjective meaning "Having the tongue forked."
Fissilingual has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings fi & ilingual which should not be misspelled with single 'S'
Wrong Spelling:  fi-s-ilingual  Correct Spelling:  fi-ss-ilingual 
Check more misspelled words of Fissilingual to spell it correct.