A duck on the lake’s centre, in a wood (3)
I believe the answer is:
Here is my best explanation:
'a wood' is the definition.
(oak is a kind of wood)
'a duck on the lake's centre' is the wordplay.
'a duck' becomes 'o'.
'on' says to put letters next to each other.
'centre' indicates the central letters.
The middle letters of 'lake' are 'ak'.
'in' is the link.