Acies - A Church function which is held annually about the Feast of the Annunciation for the members to renew their consecration to Mary.

Allocutio
- Short address by the Spiritual Director or the president, given at each Legion Meeting.

Auxiliary
- A member who supports the Legion work by the daily recitation of the rosary and the Legion prayers.

Catena
- Prayer to be recited daily by all active and Auxilliary members, consisting of the Magnificat with antiphon, versicle and the prayer from the Feast of Mary, Mediatrix of All Graces.

Comitium
- A Curia which is supervising one or more other Curiae.

Concilium
- Central International Council of the Legion of Mary in Dublin, Ireland.

Curia
- Body governing several Praesidia in a city, town or district. The officers of all the Praesidia meet once a month to discuss common problems; also the Curia supervises and controls its affiliated Praesidia which it has to visit periodically, if possible twice a year.

Handbook
- The Legion constitutions (some 350 pages). It contains nor only details of organisation, but above all the Legion spirituality. The book was originally blue in color, but was changed to red in honor of the Chinese martyrs. The front cover is decorated with the Legion Picture.

Praesidium
- Parochial or other branches of the Legion of Mary. It has five officers: spiritual director, president, vice president, secretary, treasurer. For the setting up of a Praesidium, the permission of the Bishop and parish priest is necessary.

Praetorians
- Higher grade of active membership where in addition to the usual duties (weekly meeting and solid apostolic work) the members undertake the recitation of all the prayers comprised in the Tessera of the Legion; daily Mass and daily Holy Communion; and the daily recitation of some form of Office approved by the Church.

Regia
- A council designated by the Concilium to exercise authority over the Legion of Mary in a large region.

Senatus
- A council designated by the Concilium to exercise authority over the Legion of Mary in a country or in a large area of a country.

Tessera
- The prayer card of the Legion of Mary.

Vexillium
- The standard of the Legion of Mary, an adaptation of the standard of the ancient Roman Legion. The eagle is replaced by the Dove, the emblem of the Holy Ghost, the portrait of the emperor or consul by the Miraculous Medal.