Back at last, decided to watch Puss in Boots (4)
I believe the answer is:
shod
'in boots' is the definition.
(I've seen this before)
'back at last decided to watch puss' is the wordplay.
'back' says the letters should be written in reverse.
'at last' indicates one should take the final letters.
The last letters of 'decided to watch puss' are 'dohs'.
'dohs' reversed gives 'SHOD'.
(Other definitions for shod that I've seen before include "Like a horse that's been to a farrier" , "Wearing shoes" , "in Boots?" , "Wearing footgear" , "Not barefoot" .)