Accesional or Accessional: How To spell?
The word Accesional is misspelled against Accessional, an adjective meaning "Pertaining to accession; additional."
Accessional has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings acce & ional which should not be misspelled with single 'S'
Wrong Spelling:  acce-s-ional  Correct Spelling:  acce-ss-ional 
Find more incorrect spellings of Accessional to spell right way.