Sheep's wandering around end of farmer's fields (7)
I believe the answer is:
spheres
'fields' is the definition.
('sphere' can be a synonym of 'field')
'sheep's wandering around end of farmer's' is the wordplay.
'wandering' is an anagram indicator.
'around' indicates putting letters inside.
'end of' suggests the final letters.
The final letter of 'farmer' is 'r'.
'sheeps' anagrammed gives 'sphees'.
'sphees' going around 'r' is 'SPHERES'.
(Other definitions for spheres that I've seen before include "Areas" , "Globes" , "balls" .)