Pretermision or Pretermission: How To spell?
The word Pretermision is misspelled against Pretermission, a noun meaning "The act of passing by or omitting; omission."
Pretermission has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings pretermi & ion which should not be misspelled with single 'S'
Wrong Spelling:  pretermi-s-ion  Correct Spelling:  pretermi-ss-ion 
Find more incorrect spellings of Pretermission to spell right way.