Meaning of the Sanskrit Word: vaitaranyam

  vaitaranyam—in Vaitarani, the river of suffering    SB 2.2.7
  vaitaranyam—named Vaitarani    SB 5.26.22
  vaitaranyam—in the river known as Vaitarani (which lies in front of the doorway of Yamaraja, the superintendent of death)    SB 7.9.41

Can't find any compound Sanskrit words containing vaitaranyam.