Horse-like creatures from Oxford and Cambridge perhaps eating grain (8)
I believe the answer is:
unicorns
'horse-like creatures from oxford' is the definition.
I can't judge whether this defines the answer.
'cambridge perhaps eating grain' is the wordplay.
'cambridge perhaps' becomes 'unis' (I can't explain this - if you can you should believe this answer much more).
'eating' means one lot of letters goes inside another.
'grain' becomes 'corn' (corn is a kind of grain).
'unis' placed around 'corn' is 'UNICORNS'.
'and' is the link.
Can you help me to learn more?
(Other definitions for unicorns that I've seen before include "One-horned animals of myth" , "Coins run off these imaginary creatures" , "Mythical horned creatures" , "Mythical one-horned creatures" , "Imaginary one-horned horses" .)