Possibly sat at the ringside with some food (4)
I believe the answer is:
oats
'some food' is the definition.
(I've seen this before)
'possibly sat at the ringside' is the wordplay.
'possibly' indicates an anagram.
'at' means one lot of letters go next to another (I've seen this in other clues).
'the ringside' becomes 'o' (I can't justify this - if you can you should believe this answer much more).
'sat' anagrammed gives 'ats'.
'ats' after 'o' is 'OATS'.
'with' is the link.
Can you help me to learn more?
(Other definitions for oats that I've seen before include "Seed grasses" , "Cereal plants" , "A cereal crop" , "Cereal food for horses" , "Cereal for porridge" .)