Lexical Definition

‎συμπόσιον‎ sympósion (soom-pos'-ee-on) common meal G:N-N
neuter of a derivative of the alternate of ‎συμπίνω‎

company.

Usage: 2 forms in 3 verses
Form Translated As     In Verse(s)
συμπόσια groups Mark.6.39Mark.6.39
συμποσίου party LXX.Esth.7.7

Liddell-Scott-Jones

συμπόσιον-ον, τό,

drinking-party, symposium, [Refs 7th c.BC+]; σ. κατασκευάσαι, φίλοις παρασχεῖν, συνάγειν, [Refs 5th c.BC+]

__II the party itself, the guests, [LXX+1st c.AD+]; ἀνακλιθῆναι.. συμπόσιονα συμπόσιονα in groups, [NT]
__III the room in which such parties were given, τοῦ σ. στέγη [Refs 3rd c.BC+]; σαίρειν τὸ σ. [Refs 2nd c.AD+]

LSJ Scripture Refs: Mark.6.39