Tidy in one attempt (4)
I believe the answer is:
neat
'tidy' is the definition.
(synonyms)
'in one attempt' is the wordplay.
'in' indicates the answer is hidden within the clue.
'NEAT' is hidden within 'one attempt'.
(Other definitions for neat that I've seen before include "without ice?" , "well-kept" , "As whisky may be" , "Finished" , "Bovine animal" .)