Unwilling cattle run wild (9)
I believe the answer is:
reluctant
'unwilling' is the definition.
(similar in meaning)
'cattle run wild' is the wordplay.
'wild' indicates anagramming the letters.
'cattle'+'run'='cattlerun'
'cattlerun' anagrammed gives 'RELUCTANT'.
(Other definitions for reluctant that I've seen before include "not being willing" , "Indisposed" , "Hesitant, disinclined" , "Not wishing to" , "Unwilling, disinclined" .)