Meaning of the Sanskrit Word: dustyaja

  dustyaja—although very difficult to give up    SB 5.8.26
  dustyaja—which are extremely hard to give up    SB 8.20.7
  dustyaja—difficult to give up    Adi 4.167-169
  dustyajā—extremely difficult to give up    SB 9.19.16

Can't find any compound Sanskrit words containing dustyaja.