Meaning of the Sanskrit Word: pitrn

  pitṝn—forefathers    SB 3.3.26, SB 4.27.11
  pitṝn—the forefathers    SB 3.32.2, SB 3.32.17
  pitṝn—fathers    Bg 1.26
  pitṝn—to ancestors    Bg 9.25
  pitṝn—about the denizens of the Pitṛloka planet    SB 1.16.31
  pitṝn—the residents of Pitṛloka    SB 2.3.8
  pitṝn—the Pitās    SB 6.6.19
  pitṝn—unto the forefathers    SB 7.14.15

Can't find any compound Sanskrit words containing pitrn.