Meaning of the Sanskrit Word: tvastuh

  tvastuh—of the brahmana known as Tvasta    SB 6.17.38
  tvastuh—from Tvasta    SB 5.15.14, SB 5.15.15, SB 5.15.14-15
  tvastuh—of Tvasta    SB 6.6.44

Can't find any compound Sanskrit words containing tvastuh.