Smothness or Smoothness: How To spell?
The word Smothness is misspelled against Smoothness, a noun meaning "Quality or state of being smooth."
Smoothness has double "oo" is mispronounced as "o"Remember double 'OO' in between the strings sm & thness which should not be misspelled with single 'O'
Wrong Spelling:  sm-o-thness  Correct Spelling:  sm-oo-thness 
Find more incorrect spellings of Smoothness to spell right way.