No, it is not a preposition. The word undone is a past tense verb that can also be used as an adjective.
Irreversible means unable to be undone or reversed. If something has done "irreversible damage", it means that the damage will not heal.
Its done. Un is the prefix. Undone has no suffix though. Its done. Un is the prefix. Undone has no suffix though.
No.
it means that he is coming undone because he is tired of the crap he is putting up with now
its comparing the bellowing rain and the undone curtins and that is what it means
To have come undone means that the end result of something is not what one had expected, particularly in a precarious situation where there are a number of possible outcomes.
wish reversal or to retract a wish
The letters 'dnuneo' can be unscrambled to spell one word. They rearrange to spell the word undone.
it is moral cowardice to leave undone what one perceives to be right to do means?
that means the it can not be undone because another substance was introduced
Undone is correct.