Meaning of the Sanskrit Word: naisthiki

  naisthiki—unflinching    SB 4.22.20
  naisthiki—irrevocable.    SB 1.2.18
  naisthiki—fixed    SB 4.22.26
  naisthiki—without cessation    SB 10.1.15

Can't find any compound Sanskrit words containing naisthiki.