Watery spot surrounding dock (6)
I believe the answer is:
sloppy
'watery' is the definition.
(thesaurus)
'spot surrounding dock' is the wordplay.
'spot' becomes 'spy' (synonyms).
'surrounding' is an insertion indicator.
'dock' becomes 'lop' (both can mean to cut).
'spy' placed around 'lop' is 'SLOPPY'.
(Other definitions for sloppy that I've seen before include "Lacking neatness and order" , "'Careless, shoddy (6)'" , "Mawkish" , "Slipshod" , "maudlin" .)