noun
plural -gins
[count] the part of a page that is above, below, or to the side of the printed part
the place where something (such as a piece of land) stops :the edge of something
an extra amount of something (such as time or space) that can be used if it is needed
If you have little or no margin for/of error, it means that you need to be very careful not to make mistakes. If you have a greater margin for/of error, you can be less careful.
a measurement of difference
A margin of error is a number or percentage that shows how accurate a measurement is.