Had endless yen for fodder (3)
I believe the answer is:
hay
'fodder' is the definition.
(hay is a kind of fodder)
'had endless yen' is the wordplay.
'endless' means to remove the last letter.
'yen' becomes 'y'.
'had' with its last letter taken off is 'ha'.
'ha'+'y'='HAY'
'for' acts as a link.
(Other definitions for hay that I've seen before include "Welsh festival" , "Wye book town" , "Dried mown grass" , "It is to be made while the sun shines" , "Meadow crop" .)