Weaknes or Weakness: How To spell?
The word Weaknes is misspelled against Weakness, a noun meaning "That which is a mark of lack of strength or resolution; a fault; a defect."
Weakness has double 'ss' in the end mispronounced as 's'Remember double 'SS' appears in the end of this word which should not be misspelled with single 'S'
Wrong Spelling:  weakne-s  Correct Spelling:  weakne-ss 
Explore spell check of Weakness to spell without errors.