Superadition or Superaddition: How To spell?
The word Superadition is misspelled against Superaddition, a noun meaning "The act of adding something in excess or something extraneous; also, something which is added in excess or extraneously."
Superaddition has double "dd" is mispronounced as "d"Remember double 'DD' in between the strings Supera & ition which should not be misspelled with single 'D'
Wrong Spelling:  Supera-d-ition  Correct Spelling:  Supera-dd-ition 
Check more misspelled words of Superaddition to spell it correct.