This root form (lemma) is used in 3 different forms in the NT: ἀρίστου (GNS), ἄριστον (ANS), ἄριστόν (ANS).
It is glossed in 2 different ways: ‘a dinner’, ‘dinner’.
OET MAT 22:4 Greek word=ἄριστόν (ariston) Morphology=ANS English gloss=‘dinner’ SR GNT MAT 22:4 word 11
OET LUKE 11:38 Greek word=ἀρίστου (aristou) Morphology=GNS English gloss=‘dinner’ SR GNT LUKE 11:38 word 20
OET LUKE 14:12 Greek word=ἄριστον (ariston) Morphology=ANS English gloss=‘a dinner’ SR GNT LUKE 14:12 word 10