subdeacon

noun
  1. 1

    (chiefly historical) A Catholic clerical rank in the major orders below that of a deacon.

  2. 2

    (chiefly historical) A Catholic cleric who assists the deacon at High Mass and normally reads the Epistle at the Eucharist.

  3. 3

    The highest of the minor orders below that of a deacon

Source: https://en.wiktionary.org/wiki/subdeacon