Meaning of the Sanskrit Word: duratyayam

  duratyayam—insurmountable.    SB 4.2.27, SB 8.24.51
  duratyayam—very difficult to cross    SB 9.8.13, SB 10.1.5-7
  duratyayam—very difficult    SB 1.19.2
  duratyayam—unsurpassable    SB 4.12.8
  duratyayam—impossible to overcome    SB 4.27.3

Can't find any compound Sanskrit words containing duratyayam.