Synaptic is a "front-end" to what is part of the Debian way of doing things... Apt...

apt-get install [something
apt-get remove [something]

and if you want to remove something with all of its config files, etc... like a total removal, then...

apt-get --purge remove [something]

and if you want to re-install something, you can either just re-do the apt-get install, or add the following:

apt-get --reinstall install [something]