### Clue: It's not nice to be harsh (5)
### Answer: ROUGH 
 ### Explanation: Definition: It's not nice,harsh
  Double defn:  1st: From nice = exact, as in "it fits nicely", and not nice = approximate, as in "a rough calculation"; 2nd: Sharp,coarse,harsh as in "a rough temper", or grating or unpleasant as in "sounds that are rough to the ears"