What does "Interference engine application" mean?

  "Interference engine" means that it is likely the engine could be damaged if the timing belt breaks. Most Honda engines are interference engines. If the belt were to break or skip the piston and valves will smash into each other causing damage. On an interference engine you do not want to wait till the belt or chain breaks before you replace it because the cam and crank get out of time because it will result in catastrophic engine damage.
  In interference engine designs, regular belt or chain service is especially important as incorrect timing may result in the pistons and valves colliding and causing extensive engine damage and therefore costly repairs.