durasadam
durāsadam — formidable; BG 3.43
durāsadam — very difficult to reach; SB 3.8.31
durāsadam — difficult to approach; SB 6.10.19-22
durāsadam — very difficult to conquer; SB 7.8.19-22
su-durāsadam — very difficult to approach (Lord Nṛsiṃhadeva); SB 7.9.1
durāsadam — difficult to enter; SB 10.17.8
durāsadām — inviolable; SB 10.41.20-23
durāsadam — unapproachable; SB 10.76.8