Demisionary or Demissionary: How To spell?
The word Demisionary is misspelled against Demissionary, an adjective meaning "Pertaining to transfer or conveyance; as, a demissionary deed."
Demissionary has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings demi & ionary which should not be misspelled with single 'S'
Wrong Spelling:  demi-s-ionary  Correct Spelling:  demi-ss-ionary 
Find more incorrect spellings of Demissionary to spell right way.