"Rebuy" is an overloaded term.
In the poker tournament world, the term "Rebuy" typically refers to the cost to acquire additional chips once you are already entered in a tournament. Some examples:
In Dr. Neau's Tournament Manager, the word "rebuy" represents something very specific. It is an instance of a player "rebuying". A tournament managed in the application can actually define multiple options by which people can "rebuy"...these are called "rebuy options"...and when a player execises one of those options that creates a "Rebuy" record.
Sorry for the confusion...it really doesn't matter, but you'll see references to each so I wanted to make sure you understood the reasoning behind it.