Grasing or Grassing: How To spell?
The word Grasing is misspelled against Grassing, which is present continuous of "Grass"
Grassing has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings gra & ing which should not be misspelled with single 'S'
Wrong Spelling:  gra-s-ing  Correct Spelling:  gra-ss-ing 
Find more wrongly spelled words of Grassing to spell it well.