Shabby, putting stone on your head (5)
I believe the answer is:
seedy
'shabby' is the definition.
(I've seen this before)
'stone on your head' is the wordplay.
'stone' becomes 'seed' (eg the stone from a fruit).
'on' is a charade indicator (letters next to each other).
'head' indicates taking the first letters.
The initial letter of 'your' is 'y'.
'seed'+'y'='SEEDY'
'putting' acts as a link.
(Other definitions for seedy that I've seen before include "Unfit" , "Sleazy, sordid" , "Nasty and squalid" , "under the weather" , "Sordid, squalid" .)