Ducks, say (6)
I believe the answer is:
avoids
'ducks say' is the definition.
(ducking is a kind of avoiding)
This is the entire clue.
(Other definitions for avoids that I've seen before include "Steers clear of, dodges" , "Shuns, keeps away from" , "Stays away from" , "Ducks (out of)" , "Escapes" .)