Meaning of the Sanskrit Word: trtiyam

  tṛtīyam—the third    SB 8.22.2, Adi 5.77, Madhya 20.251
  tṛtīyam—the third one    SB 1.3.8
  tṛtīyam—the third month    SB 4.8.74
  tṛtīyam—third    SB 6.18.7
  tṛtīyam—for the third step    SB 8.21.29
  tṛtīyam—and a third son    SB 9.24.1
  tṛtīyām—the third wife    SB 8.13.9

Can't find any compound Sanskrit words containing trtiyam.