Took a seat to eat pork, oddly, and fish (5)
I believe the answer is:
sprat
'fish' is the definition.
(sprat is a kind of fish)
'took a seat to eat pork oddly' is the wordplay.
'took a seat' becomes 'sat' (I've seen this before).
'to eat' indicates putting letters inside.
'oddly' indicates alternate letters.
The alternating letters of 'pork' are 'pr'.
'sat' enclosing 'pr' is 'SPRAT'.
'and' is the link.
(Other definitions for sprat that I've seen before include "Small herring, often smoked or canned" , "Small marine fish" , "little fish" , "Small sea fish" , "Jack --, non-fat eater" .)