Meaning of the Sanskrit Word: trastah

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

Can't find any compound Sanskrit words containing trastah.