Impermisible or Impermissible: How To spell?
The word Impermisible is misspelled against Impermissible, an adjective meaning "Not permissible."
Impermissible has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings impermi & ible which should not be misspelled with single 'S'
Wrong Spelling:  impermi-s-ible  Correct Spelling:  impermi-ss-ible 
Find more wrongly spelled words of Impermissible to spell it well.