Something that can not be undone or undo [closed]

Question

A word for something that can't be undone or undo ?

Answer 1

"irreversible"

 -  not able to be undone or altered.
 - not able to be reversed.

source.

or

"irrevocable"

not able to be revoked, changed, or undone.

source.

Answer 2

Synonyms for "permanent" from NOAD 2011:

lasting, enduring, indefinite, continuing, perpetual, everlasting, eternal, abiding, constant, irreparable, irreversible, lifelong, indissoluble, indelible, standing, perennial, unending, endless, never-ending, immutable, undying, imperishable, indestructible, ineradicable, ineliminable; literary sempiternal, perdurable, long-term, stable, secure, durable.

Synonyms for "secure" from NOAD 2011:

fastened, fixed, secured, done up; closed, shut, locked, safe, protected, sheltered, certain, assured, reliable, dependable, settled, fixed.

Answer 3

not a single word but

written in stone (or carved in stone/engraved in stone)

Fig. permanent or not subject to change. (Often in the negative.) Now, this isn't carved in stone yet, but this looks like the way it's going to be. Is this policy carved in stone, or can it still be modified? - The Free Dictionary

Like the definition says - it is usually used in the negative, but you can use it the other way for emphasis as well.

Answer 4

"At(or beyond) the point of no return"