This root form (lemma) is used in 2 different forms in the NT: ζεύγη (ANP), ζεῦγος (ANS).
It is glossed in 2 different ways: ‘a pair’, ‘pairs’.
OET LUKE 2:24 Greek word=ζεῦγος (zeugos) Morphology=ANS English gloss=‘a pair’ SR GNT LUKE 2:24 word 12
OET LUKE 14:19 Greek word=ζεύγη (zeugaʸ) Morphology=ANP English gloss=‘pairs’ SR GNT LUKE 14:19 word 4