A deaconess is a woman set apart for a ministry of service in the church, an office of the early church that was later revived in modern Protestantism and Orthodoxy.
The ancient office
In the early church the deaconess was a woman set apart to assist in the ministry to women, notably at the baptism of women, which for reasons of modesty required a woman assistant, and in the care of the sick and the poor and the instruction of female converts, so the office was one of service directed particularly toward women and the needy. In the Eastern church the deaconesses were ordained with a rite that closely resembled the ordination of male deacons, which is why scholars debate whether they held the same order, and the office flourished for several centuries before it declined.
Revival and the modern question
The office was revived in the nineteenth century, first in Protestant churches, where communities of deaconesses were founded for nursing, teaching and charitable work, and the movement spread widely, and there has been renewed attention to the ancient female diaconate in the Orthodox and Catholic churches, where the question of restoring it, and whether it would be the same order as the male diaconate, is under discussion. In churches that now ordain women, the female diaconate is simply part of the ordained ministry. The deaconess thus represents both an ancient office of women service in the church and a modern revival of it, and the historical evidence of the ordained deaconesses of the early church stands at the centre of present debates over the ministry of women.