This root form (lemma) is used in 3 different forms in the NT: ἀριστήσατε (MAA2··P), ἀριστήσῃ (SAA3··S), ἠρίστησαν (IAA3··P).
It is glossed in 3 different ways: ‘he may eat_breakfast’, ‘they ate_lunch’, ‘eat_breakfast’.
OET JOHN 21:12 Greek word=ἀριστήσατε (aristaʸsate) Morphology=MAA2··P English gloss=‘eat_breakfast’ SR GNT JOHN 21:12 word 6
OET JOHN 21:15 Greek word=ἠρίστησαν (aʸristaʸsan) Morphology=IAA3··P English gloss=‘they ate_lunch’ SR GNT JOHN 21:15 word 3
OET LUKE 11:37 Greek word=ἀριστήσῃ (aristaʸsaʸ) Morphology=SAA3··S English gloss=‘he may eat_breakfast’ SR GNT LUKE 11:37 word 16