Turkey meal comes round with dinners originally for four (6)
I believe the answer is:
tetrad
'four' is the definition.
(synonyms)
'turkey meal comes round with dinners originally' is the wordplay.
'turkey' becomes 'tr' (abbreviation eg in internet addresses).
'meal' becomes 'tea' (tea is a type of meal).
'comes round' indicates putting letters inside.
'with' is a charade indicator (letters next to each other).
'originally' says to take the initial letters.
The first letter of 'dinners' is 'd'.
'tr' put within 'tea' is 'tetra'.
'tetra'+'d'='TETRAD'
'for' acts as a link.
(Other definitions for tetrad that I've seen before include "quartet" , "Group or set of four" , "number of Gospel writers" .)