Meaning of the Sanskrit Word: vastutah

  vastutah—in fact    Adi 16.97, Madhya 1.225, Antya 4.198
  vastutah—factually    Adi 7.123, Madhya 22.29
  vastutah—the original substance.    SB 5.18.5
  vastutah—in fact.    SB 7.13.5
  vastutah—at the ultimate issue    SB 6.8.31
  vastutah—with the proper ingredients    SB 5.19.26
  vastutah—and paraphernalia    SB 8.23.16

Can't find any compound Sanskrit words containing vastutah.