* Reversal:
* Undo: to reverse the effect of something.
* Untie: to loosen a knot.
* Unpack: to take things out of a container.
* Negation:
* Unhappy: not happy.
* Uncertain: not certain.
* Unimportant: not important.
* Lack of:
* Unprepared: not ready.
* Unpaid: not paid.
* Unseen: not visible.
It's important to note that the exact meaning of "un-" can sometimes be influenced by the word it's attached to. For example, "unnatural" implies something that is not typical or expected, while "unhealthy" simply means not healthy.
Overall, "un-" is a very common prefix that adds a negative or opposite meaning to a word.