> Master/slave is a model of asymmetric communication or control where one device or process controls one or more other devices or processes and serves as their communication hub.

Exactly. That's why it's a bad choice of name for IDE controllers and for the main boot record, where the master does not control the slave.

> inb4 we can sacrifice accuracy over feeling

Firmly agree that we should not sacrifice accuracy over feeling. I have no sympathy for people whose feelings are hurt because they're told that "master"/"slave" terminology is inaccurate. Facts don't care about your feelings.