Sheep in more trouble (6)
I believe the answer is:
merino
'sheep' is the definition.
(breed of sheep)
'in more trouble' is the wordplay.
'trouble' indicates anagramming the letters.
'in'+'more'='inmore'
'inmore' with letters rearranged gives 'MERINO'.
(Other definitions for merino that I've seen before include "Long-haired sheep" , "Australian sheep" , "Breed of sheep with fine wool" , "The sheep provides fine wool" , "Fine woollen yarn" .)