Tidy section of hemline a tad (4)
I believe the answer is:
neat
'tidy' is the definition.
(similar in meaning)
'section of hemline a tad' is the wordplay.
'section of' indicates a hidden word.
'NEAT' is hidden within 'hemline a tad'.
(Other definitions for neat that I've seen before include "Clever" , "Taken without water" , "Shipshape" , "Excellent American" , "Finished" .)