Help alphabetise clothes (4)
I believe the answer is:
abet
'help' is the definition.
(thesaurus)
'alphabetise clothes' is the wordplay.
'clothes' indicates the answer is hidden within the clue (the letters clothe the hidden word).
'ABET' can be found hidden inside 'alphabetise'.
(Other definitions for abet that I've seen before include "Aid (a criminal)" , "Beat up by way of help" , "Encourage or assist (someone) to commit crime" , "Assist (a criminal)" , "Assist (in wrongdoing)" .)