Meaning of the Sanskrit Word: puratanam

  puratanam—very old    SB 4.25.9, SB 7.2.27
  puratanam—which is very old    SB 6.1.20
  puratanam—very, very old    SB 7.13.11
  puratanam—the oldest of everyone    SB 8.23.1

Can't find any compound Sanskrit words containing puratanam.