Overruning or Overrunning: How To spell?
The word Overruning is misspelled against Overrunning, which is present continuous of "Overrun"
Overrunning has double "nn" is mispronounced as "n"Remember double 'NN' in between the strings overru & ing which should not be misspelled with single 'N'
Wrong Spelling:  overru-n-ing  Correct Spelling:  overru-nn-ing 
Check more misspelled words of Overrunning to spell it correct.