Scoffing oriental king is tucking into fish (8)
I believe the answer is:
derisory
'scoffing' is the definition.
(I've seen this before)
'oriental king is tucking into fish' is the wordplay.
'oriental' becomes 'e'.
'king' becomes 'R' (abbreviation for rex, king in Latin).
'tucking into' indicates putting letters inside.
'fish' becomes 'dory' (dory is a kind of fish).
'e'+'r'+'is'='eris'
'eris' placed inside 'dory' is 'DERISORY'.
(Other definitions for derisory that I've seen before include "worthy of scorn?" , "Deserving of ridicule, laughable" , "Insultingly small" , "Contemptible" , "pathetically small" .)