inexcusablein‧ex‧cu‧sa‧ble /ˌɪnɪkˈskjuːzəbəl◂/ adjective  
 
- Anyone can make a mistake, but to ignore basic safety regulations is quite inexcusable.
- Being late for your own wedding is inexcusable.
- It is inexcusable that the government has never paid a cent to the widows of these brave men.
behaviour that cannot be forgiven► unforgivable/unforgiveable behaviour that is unforgivable  is so bad that you cannot forgive it: · The way you spoke to your mother was unforgivable.· It was an unforgiveable thing to do.
► inexcusable an action or situation that is inexcusable  cannot be excused and someone must be blamed for it, because there is no good reason for it: · Anyone can make a mistake, but to ignore basic safety regulations is quite inexcusable.it is inexcusable that: · It is inexcusable that the government has never paid a cent to the widows of these brave men.
  nounexcuseadjectiveexcusable ≠ inexcusableverbexcuseadverbinexcusably