nondefeasible

• a word derived from defeasible.
  defeasible

  adjective

  capable of being annulled or terminated.

Related Words

• feeble
• fruitless
• futile
• impotent
• inadequate
• incompetent
• indecisive
• ineffectual
• inefficient
• inept
• limited
• null
• powerless
• unable
• unproductive
• unprofitable
• unsuccessful
• worthless