$ sudo apt-get remove lwatch 

Uninstall lwatch including dependent package

If you would like to remove lwatch and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove lwatch 

Use Purging lwatch

If you use with purge options to lwatch package all the configuration and dependent packages will be removed.

$ sudo apt-get purge lwatch 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove lwatch 

See Also,