An officer in Christian churches appointed to perform
   certain subordinate duties varying in different communions. In the
   Roman Catholic and Episcopal churches, a person admitted to the lowest
   order in the ministry, subordinate to the bishops and priests. In
   Presbyterian churches, he is subordinate to the minister and elders,
   and has charge of certain duties connected with the communion service
   and the care of the poor. In Congregational churches, he is subordinate
   to the pastor, and has duties as in the Presbyterian church.