Meaning of the Sanskrit Word: rasatalam

  rasatalam—to the depths of the ocean    SB 3.18.1
  rasatalam—to the lower region of the universe    SB 9.7.2
  rasatalam—Rasatala    SB 5.24.7
  rasatalam—the planets named Rasatala    SB 2.1.26
  rasatalam—the sixth planetary system below    SB 2.5.40, SB 2.5.41, SB 2.5.40-41
  rasatalam—to Patala, the lower part of the universe.    SB 9.9.4

Can't find any compound Sanskrit words containing rasatalam.