Eliot, I have lived for years in the same religious community as many "consagrados" and in English they are referred to as consecrated men or women.
The reality of consecrated life is something that began in the 60's and 70's. While similar to religious brothers and nuns ("religiosos"), consecrated men and women take promises of poverty, chastity and obedience, while religious take vows.
In reference to the other entries on this page, other words like "devotee" and "dedicated" are descriptive, but do not translate this specific term within the Catholic Church. "Acolyte" is something totally different, a ministry usually in preparation for the priesthood; also refers to an altar server.

Here are some examples from the web:

http://www.regnumchristi.org/english/articulos/articulo.phtm...
Consecrated Men in Regnum Christi
Giving everything for Christ as consecrated lay missionaries



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Note added at 9 hrs (2006-09-02 03:11:20 GMT)
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Eliot, official documents from the Church on Consecrated Life:

http://www.vatican.va/holy_father/john_paul_ii/apost_exhorta...
POST-SYNODAL
APOSTOLIC EXHORTATION
VITA CONSECRATA
OF THE HOLY FATHER
JOHN PAUL II

It was my wish that the Synodal Assembly should include, together with the Bishops, a considerable number of consecrated men and women, in order that they too might contribute to the common reflection.

In every age consecrated men and women must continue to be images of Christ the Lord, fostering through prayer a profound communion of mind with him (cf. Phil 2:5-11)

... also hope that consecrated men and women, in full harmony with the Church and her Magisterium, will discover in this Exhortation further encouragement to face in a spiritual and apostolic manner the new challenges of our time

Although these different categories are a manifestation of the one mystery of Christ, the lay faithful have as their specific but not exclusive characteristic, activity in the world; the clergy, ministry; consecrated men and women, special conformity to Christ, chaste, poor and obedient.

http://www.vatican.va/holy_father/john_paul_ii/speeches/2005...

SPECIAL MESSAGE OF POPE JOHN PAUL II
FOR WORLD DAY OF CONSECRATED LIFE

Just as Christ makes himself "bread broken" and "blood poured out", so each Christian, and especially every consecrated man and every consecrated woman, is called to give his or her life for the brethren, in union with the life of the Redeemer.