Meaning of the Sanskrit Word: krsnau

  kṛṣṇau—Śrī Kṛṣṇa    SB 1.3.23
  kṛṣṇau—the two Kṛṣṇas (Kṛṣṇa and Arjuna)    SB 4.1.59

Can't find any compound Sanskrit words containing krsnau.