Duck leaves drink by lake (4)
I believe the answer is:
teal
'duck' is the definition.
(teal is a type of duck)
'drink by lake' is the wordplay.
'drink' becomes 'tea' (tea is a drink).
'by' says to put letters next to each other.
'lake' becomes 'L' (geographical abbreviation).
'tea'+'l'='TEAL'
'leaves' acts as a link.
(Other definitions for teal that I've seen before include "bird" , "Small freshwater duck and colour" , "Small river duck" , "Variety of duck" , "Type of duck" .)