Greek character throws up less seafood (6)
I believe the answer is:
mussel
'seafood' is the definition.
(mussel is a kind of seafood)
'greek character throws up less' is the wordplay.
I cannot really see how this works, but
'character' could be 'mu' (Greek letter) and 'mu' is found in the answer.
an anagram of 'less' is 'ssel' which is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for mussel that I've seen before include "The shellfish sounds strong" , "Edible marine mollusc sold by Molly Malone - not the cockle" , "Bivalve with purple-black shell" , "Black marine bivalve" , "Type of shellfish" .)