That can not be altered or withdrawn - irrevocable (स्थिर)
That is prohibited by law - illicit (अवैध)
That through which light can partly pass - translucent (पारदर्शी)
That through light can not pass - opaque (अपारदर्शी)
That which can not be avoided - inevitable (अनिवार्य)
That which can not be believed - incredible (अविश्वसनीय)
That which can not be conquered - invincible (अजेय)
That which can not be cured - incurable (लाइलाज)
That which can not be defended - indefensible (अरक्षणीय)
That which can not be described - indescribable (अवर्णनीय)