Fixed quickly (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
fast
This clue is a double definition.
'fixed' is the first definition.
(I've seen this before)
'quickly' is the second definition.
('fast' can be a synonym of 'quickly')
(Other definitions for fast that I've seen before include "Period during which fare is reduced" , "sort of convenience food" , "Brisk" , "Express" , "Rapidly; tight" .)