Definition of "checkout"

The process of checking out of a hotel, or the latest time to vacate a room in one.  examples

The process of checking out items at a supermarket or library.  examples

The place in a supermarket where this is done.  examples

(Internet, by extension) The process of confirming and paying for an online purchase.  examples

A test to see if some device is functioning properly.  examples

An inspection or investigation.  examples

(darts) The number of points that a player scores on their final, winning visit to the oche.  examples