Rom. 16:1, 3, 12; Phil. 4:2, 3; 1 Tim. 3:11; 5:9, 10; Titus 2:3, 4). In these passages it is evident that females were then engaged in various Christian ministrations. Pliny makes mention of them also in his letter to Trajan (A.D. 110).
Dictionary entry
Deaconess
Easton's Bible Dictionary