Mixin, Mixins:

1. A reference to the Mixin Subsystem, see Introduction to Mixins (WIP)
2. “a Mixin” or “a Mixin Class” means a class or, for the former especially, an interface that will be merged with a target by the Mixin system.

Injector:

1. Most of the time, references a “callback injector”, or an annotated handler method that will be merged by a Mixin Class, with a callback to the merged method at a specified injection point. This most often does not include Redirectors, although they may also be considered injectors under technical definitions.

Handler method:

1. In the context of Mixins, a decorated method that will be merged and then called to in some way dependent on the annotation and its arguments.