Preclude (4,3)
![Ross](/clue/static/ross-mug.min.png)
'preclude' is the definition.
(I know that preclude can be written as rule out)
This is the entire clue.
(Other definitions for rule out that I've seen before include "Exclude from consideration" , "'Eliminate from consideration (4,3)'" , "discount" , "Exclude as a possibility" , "Eliminate, exclude as irrelevant" .)
(Other definitions for disqualify that I've seen before include "Exclude" , "Declare unsuitable" , "Remove from competition" .)