Main course (6)
'main course' is the definition.
(synonyms)
This is all the clue.
(Other definitions for entree that I've seen before include "The right ot privilege of admission" , "Means of access - course" , "Privilege of admission, or food dish" , "Principal dish of a meal" , "Main course dish" .)
(Another definition for entre that I've seen is " - - nous (Fr.)".)
(Other definitions for seafood that I've seen before include "The "surf" of a surf 'n' turf dish" , "Such as prawns, tuna" , "Edible fish, shellfish etc from the oceans" , "Eaten fish and shellfish" , "Shellfish, marine fish" .)
'main course' is the definition.
(I've seen this in another clue)
This is the entire clue.