Louis Rossmann made a video giving his definition, which is that parts are available. However, that is only his definition, there is still broader community lack of focus on what it means.

Some people think it means that Apple must make their products easy to repair. Others think it means Apple must every single chip available for independent purchase. Others think it means Apple must only make available the parts that they would provide their AASPs with (only finished boards and displays, not individual chips).