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