Meaning of the Sanskrit Word: tvastuh

  tvaṣṭuḥ—from Tvaṣṭā    SB 5.15.14-15
  tvaṣṭuḥ—of Tvaṣṭā    SB 6.6.44
  tvaṣṭuḥ—of the brāhmaṇa known as Tvaṣṭā    SB 6.17.38

Can't find any compound Sanskrit words containing tvastuh.