Very hungry bird with mouse, rejecting head and tail (8)
I believe the answer is:
ravenous
'very hungry' is the definition.
(I've seen this before)
'head and tail' is the wordplay.
'head' becomes 'nous' (synonyms).
'and' means one lot of letters go next to another.
'tail' becomes 'rave' (I am not sure about this - if you are sure you should believe this answer much more).
'nous' after 'rave' is 'RAVENOUS'.
'bird with mouse rejecting' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for ravenous that I've seen before include "Really hungry, could eat a horse" , "Voraciously hungry" , "Extremely hungry" , "Really hungry, starving" , "Intensely hungry" .)