Abbott-Smith Manual Greek Lexicon
γερουσία (G1087)
1 γερουσία , -ας, ἡ ( γέρων ), [in LXX (Hex. only in OT) for זָקֵן ;] a council of elders , senate ; in NT, of the Sanhedrin ( Cl. Rev. , i, 43 f.; DB , ext. , 99): Ac 5:21 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain