Dulia
Webster's Dictionary [1]
(n.) An inferior kind of veneration or worship, given to the angels and saints as the servants of God.
Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]
( Δουλεία ), worship paid to saints and angels. In the Greek Church, a distinction is made between Λατρεία , worship due only to God, and Τιμητικὴ Προσκύνησις , adoration which may be rendered to images. Authority for this distinction is found in a decision of the second Council of Nicaea, AD 787 (sess. 7), as follows: "We decide that the holy images, whether painted or graven, or of whatever kind they may be, ought to be exposed to view, whether in churches, upon the sacred vessels and vestments, upon walls, or in private houses, or by the wayside, since the oftener Jesus Christ, his blessed mother, and the saints are seen in their images, the more will men be led to think of the originals, and to love them. Salutation and the adoration of honor ought to be paid to images, but not the worship of latria, which belongs to God alone: nevertheless, it is lawful to burn lights before them, and to incense them, as is usually done with the cross, the books of the Gospels, and other sacred things, according to the pious use of the ancients; for honor so paid to the image is transmitted to the original which it represents. Such is the doctrine of the holy fathers, and the tradition of the Catholic Church; and we order that they who dare to think or teach otherwise, if bishops or other clerks, shall be deposed; if monks or laymen, shall be excommunicated" (Landon, Manual of Councils, 437; Labbe and Cossart, Concil. 7:1-963; Mansi, Concil. 13:374 sq.; Hefele, Contiliengeschichte, § 354).
In the Roman Church a distinction is made between latria ( Λατρεία ), worship due to God; dulia ( Δουλεία ), adoration or invocation of saints and angels; and hyperdulia ( Ὑπερδουλεία ), due to the Virgin Mary alone (Council of Trent, sess. 25). Protestants, of course, reject all these distinctions. See Hagenbach, History Of Doctrines , § 188; Haag, Histoire Des Dogmes Chretiens , 2:77; Burnet, On The Articles , art. 22; and the articles IDOLATRY (See Idolatry) ; (See Image Worship); (See Invocation Of Saints).
The Nuttall Encyclopedia [3]
An inferior kind of worship paid to angels and saints, in contradistinction to Latria ( q. v .).