What is an augmentor wing?
In a blown wing, such as blown flaps, air is driven by the engines through ducts in the wing and out through various orifices to boost the airflow over the wing. This helps increase lift, especially to give good STOL performance at low forward speeds.
The augmentor wing takes the sophistication a stage further by arranging the air outlets so that the flow draws in or entrains ambient air into the wing flow, further increasing or augmenting mass flow and the efficiency of the system.
A typical example was the DHC-5 modified with an augmentor wing; a little bit about it is given on Wikipedia. The Rockwell XFV-12 was a supersonic VTOL fighter prototype, which blew the air directly downwards through vertical slots in the wing, however it did not entrain as much additional air as expected and lift augmentation levels were disappointing.
The system has never reached operational use, mainly because the weight, complexity and cost have never been justified by the performance gains.