This root form (lemma) is used in 3 different forms in the NT: εὐχήν (AFS), εὐχὴ (NFS), εὐχὴν (AFS).
It is glossed in 2 different ways: ‘a vow’, ‘vow’.
OET ACTS 18:18 Greek word=εὐχήν (euⱪaʸn) Morphology=AFS English gloss=‘a vow’ SR GNT ACTS 18:18 word 33
OET ACTS 21:23 Greek word=εὐχὴν (euⱪaʸn) Morphology=AFS English gloss=‘a vow’ SR GNT ACTS 21:23 word 11
OET JAM 5:15 Greek word=εὐχὴ (euⱪaʸ) Morphology=NFS English gloss=‘vow’ SR GNT JAM 5:15 word 3