Ravenous and unhappy, knocked up some food (7)
I believe the answer is:
wolfish
'ravenous' is the definition.
(I know that ravenous can be written as wolfish)
'unhappy knocked up some food' is the wordplay.
'unhappy' becomes 'low'.
'knocked up' says the letters should be written in reverse.
'some food' becomes 'fish' (fish is a kind of food).
'low' reversed gives 'wol'.
'wol'+'fish'='WOLFISH'
'and' is the link.
(Other definitions for wolfish that I've seen before include "like Lupus?" , "Ravenous" .)