Horse disturbing dust (4)
I believe the answer is:
stud
'horse' is the definition.
(thesaurus)
'disturbing dust' is the wordplay.
'disturbing' indicates an anagram (I've seen this in other clues).
'dust' with letters rearranged gives 'STUD'.
(Other definitions for stud that I've seen before include "Male horse kept for breeding" , "Small jewellery item" , "Collar fastener - form of poker" , "A horse breeding farm" , "card game" .)