A more thorough explanation:

NONUSER

Nonuser refers to the failure to exercise a right, such as a franchise or easement. This can result in the person having the right losing it. For example, the government may not revoke a citizen's voting right because of nonuser.

Nonuser means not using a right that you have. For example, if you have the right to vote but you don't vote, you are a nonuser of your voting right. If you don't use your right for a long time, you might lose it. The example of the government not revoking a citizen's voting right because of nonuser means that the government cannot take away a person's right to vote just because they haven't voted in a while.

Another example of nonuser could be if you have the right to use a shared driveway, but you never use it. If you don't use the driveway for a long time, the owner of the property might be able to take away your right to use it.