Meaning of the Sanskrit Word: susthu

  suṣṭhu—exceedingly    Madhya 23.40, Antya 19.105
  suṣṭhu—appropriate    SB 4.22.17
  suṣṭhu—sufficiently    SB 4.24.11
  suṣṭhu—perfectly    Adi 17.293
  suṣṭhu—nicely    Antya 16.117

Can't find any compound Sanskrit words containing susthu.