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