Meaning of the Sanskrit Word: duratyayah

  duratyayaḥ—immeasurable.    SB 2.6.18
  duratyayaḥ—which is insurmountable.    SB 9.4.14
  duratyayaḥ—insurmountable    SB 9.5.7

Can't find any compound Sanskrit words containing duratyayah.