Meaning of the Sanskrit Word: sadhusu

  sādhuṣu—unto the saintly persons    SB 7.4.27, SB 9.4.17
  sādhuṣu—unto the pious    Bg 6.9
  sādhuṣu—with saintly persons    SB 3.23.55
  sādhuṣu—to the devotees    SB 3.25.20
  sādhuṣu—with devotees    SB 6.2.39
  sādhuṣu—unto devotees    SB 9.4.69
  sādhuṣu—such saintly persons    SB 9.6.51

Can't find any compound Sanskrit words containing sadhusu.