Swiftnes or Swiftness: How To spell?
The word Swiftnes is misspelled against Swiftness, a noun meaning "The quality or state of being swift; speed; quickness; celerity; velocity; rapidity; as, the swiftness of a bird; the swiftness of a stream; swiftness of descent in a falling body; swiftness of thought, etc."
Swiftness 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:  swiftne-s  Correct Spelling:  swiftne-ss 
Find more wrongly spelled words of Swiftness to spell it well.