Meaning of the Sanskrit Word: trastah

  trastah—frightened    SB 7.9.16
  trastah—frightened    SB 3.17.12
  trastah—frightened of    SB 3.17.22
  trastah—fearful    SB 3.19.17
  trastah—being afraid    SB 4.14.3

Can't find any compound Sanskrit words containing trastah.