A "kickout station" is a station that puts you some distance away from the docking radius of the station, before your session change timer has elapsed.
You can determine if a station is a kick-out station by hitting the 'escape' key on your eve client, and on the general settings tab tick the show session change timer. Return to the game and un-dock from any station. You will note the small, rotating icon in the upper left hand side of your screen. When the icon disappears you may press the dock key and instantly re-dock...UNLESS you are outside the docking radius of the station, e.g. the distance to the station in your overview is something other than zero.
So...why is this important? If you are un-docking in a capital ship, or even a pod, as long as you do not touch a control on your ship no-one can target you for the duration of the session change timer. If you try to change course or re-dock, you will be unable to do so, but the enemies can target your ship until your undock timer has expired. If you un-dock from a non-kickout station (e.g. Jita IV, moon 4) and see a huge fleet of reds, simply remain calm, and wait for your timer to elapse. The minute it does, hit the re-dock button and you will be safely inside before anyone can harm you. Conversely, if you are in a kick-out station and undock you will need to break your session change timer to approach the station. This gives your enemies time to bump you off and/or blow you up.