Meaning of the Sanskrit Word: tvastram

  tvāṣṭram—the son of Tvaṣṭā    SB 6.7.25, SB 6.9.40
  tvāṣṭram—the demon Vṛtra (son of Tvaṣṭā)    SB 3.19.25
  tvāṣṭram—to the son of Tvaṣṭā    SB 6.7.26
  tvāṣṭram—the demon Vṛtrāsura, son of Tvaṣṭā    SB 6.9.44
  tvāṣṭram—meant for the demigod known as Tvaṣṭā    SB 6.14.27
  tvāṣṭram—performed by Tvaṣṭā    SB 8.11.35

Can't find any compound Sanskrit words containing tvastram.