Ilness or Illness: How To spell?
The word Ilness is misspelled against Illness, a noun meaning "Disease; indisposition; malady; disorder of health; sickness; as, a short or a severe illness."
Illness has double "ll" is mispronounced as "l"Remember double 'LL' in between the strings i & ness which should not be misspelled with single 'L'
Wrong Spelling:  i-l-ness  Correct Spelling:  i-ll-ness 
Explore spell check of Illness to spell without errors.