Unruly hairdo (3)
I believe the answer is:
mop
'unruly hairdo' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mop that I've seen before include "Swab" , "Cleaning implement" , "Shock of hair; soak (up)" , "Bundle of soft material at end of stick for cleaning" , "Wet cleaner" .)