Easy target (6)
'easy target' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sitting duck that I've seen before include "Helpless victim" , "Wide-open target" , "Obvious target" , "Potential victim" , "Easy target" .)
'easy target' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sitter that I've seen before include "Artist's model - an easy catch" , "Person posing for a portrait" , "eyed by a drawer?" , "Child-minder of sedentary disposition" , "Baby minder for pay" .)