From BiblePortal Wikipedia

Charles Buck Theological Dictionary [1]

An assembly of persons for the worship of God,  Leviticus 23:1-44 : Numb. 28:   Exodus 12:16 . An assembly of the clergy for consultation upon matters ecclesiastical. As the parliament consists of two distinct houses, so does this convocation. the one called the upper house, where the archbishops and bishops sit severally by themselves; the other the lower house, where all the rest of the clergy are represented by their deputies.

The inferior clergy are represented by their proctors; consisting of all the deans and archdeacons; of one proctor for every chapter, and two for the clergy, of every diocese

in all, one hundred and forty-three divines, viz. twenty-two deans, fifty-three archdeacons, twenty-four prebendaries, and forty-four proctors of the diocesan clergy. The lower house chooses its prolocutor, who is to take care that the members attend, to collect their debates and votes, and to carry their resolutions to the upper house. The convocations is summoned by the king's writ, directed to the archbishop of each province, requiring him to summon all bishops, deans, archdeacons, &c. The power of the convocation is limited by a statute of Henry VIII. they are not to make any canons, or ecclesiastical laws, without the king's license; nor, when permitted, can they put them in execution but under several restrictions.

They have the examining and censuring all heretical and schismatical books and persons, &c; but there lies an appeal to the king in chancery, or to his delegates. The clergy in convocation, and their servants, have the same privileges as members of parliament. In 1665, the convocation of the clergy gave up the privilege of taxing themselves to the house of commons, in consideration of their being allowed to vote at the election of members for that house. Since that period they have been seldom allowed to do any business; and are generally prorogued from time to time till dissolved, a new convocation being generally called along with a new parliament.

King James Dictionary [2]

Convocation n. L.

1. The act of calling or assembling by summons. 2. An assembly.

In the first day there shall be a holy convocation.  Exodus 12 .

3. In England, an assembly of the clergy, by their representatives, to consult on ecclesiastical affairs. It is held during the session of parliament, and consists of an upper and lower house. In the upper house sit the archbishops and bishops in the lower house sit the inferior clergy, represented by their proctors, consisting of all the deans and arch-deacons, of one proctor for every chapter, and two for the clergy of every diocese, in all one hundred and forty-three divines, Twenty-two deans, fifty-three arch-deacons, twenty-four prebendaries, and forty-four proctors of the diocesan clergy. 4. An academical assembly, in which the business of the university is transacted.

Morrish Bible Dictionary [3]

'A calling together,' and always called 'holy.' The occasions called 'holy convocations' are specially given in  Leviticus 23 when the Feasts are recorded; they included the Sabbath, and ended with the Feast of Tabernacles. "These are the feasts of the Lord, which ye shall proclaim to be holy convocations, to offer an offering made by fire unto the Lord."   Leviticus 23:37 . It occurs also in  Exodus 12:16;  Numbers 28:18,25,26;  Numbers 29:1,7,12 . The same Hebrew word is translated 'assemblies' in  Isaiah 1:13;  Isaiah 4:5 .

Easton's Bible Dictionary [4]

 Leviticus 23:2,3 Exodus 12:16 Leviticus 23:7,8 Numbers 28:25 Leviticus 23:21 Leviticus 23:24 Numbers 29:1 Numbers 28:26 Leviticus 23:35,36 Leviticus 23:27 Numbers 29:7

Webster's Dictionary [5]

(1): (n.) An assembly or meeting.

(2): (n.) The act of calling or assembling by summons.

(3): (n.) An assembly of the clergy, by their representatives, to consult on ecclesiastical affairs.

(4): (n.) An academical assembly, in which the business of the university is transacted.

Smith's Bible Dictionary [6]

Convocation. This term (with one exception) -  Isaiah 1:13 - is applied, invariably, to meetings of a Religious character, in contradistinction to congregation .

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [7]

( מַקְרָא , mira', from קָרָא , Kara' , to Call ; comp.  Numbers 10:2;  Isaiah 1:13), applied invariably to meetings of a Religious character, in contradistinction to Congregation , in which political and legal matters were occasionally settled. (See Government). Hence it is connected with קֹדֶשׁ , Holy , and is applied only to the Sabbath and the great annual festivals of the Jews ( Exodus 12:16;  Leviticus 23:2 sq.;  Numbers 28:18 sq.;  Numbers 29:1 sq.). In this sense, with one exception ( Isaiah 1:13, "assembly"), the word is peculiar to the Pentateuch; but in  Isaiah 4:5, it denotes the Place of gathering ("assemblies"), and in  Nehemiah 8:3, it signifies the public "Reading " of the law in the synagogue service. The Sept. treats it as an adjective ( Κλητός , Ἐπίκλητος ; Called ); but there can be no doubt that the A. V. is correct in its rendering (Smith, s.v.). (See Congregation). Like the Greek Πανηγυρις or mass-meeting (Smith's Dict. Of Class. Antiq. s.v. Panegyris), it signifies "a meeting or solemn assembly of a whole people for the purpose of worshipping at a common sanctuary." The phrase "holy convocation" is applied,

I. To the FEASTS:

1. To the Sabbaths, all of which were "holy convocations" ( Leviticus 23:2-3).

2. To the Passover .

(a.) Its First Day ( Exodus 12:16;  Leviticus 23:7;  Numbers 28:18);

(b.) Its Last Day ( Exodus 12:16;  Leviticus 23:8;  Numbers 28:25).

3. To The Pentecost ( Leviticus 23:21).

4. To The Feast Of Trumpets On The 1St Of Tisri, The New Year'S Day Of The Civil Year ( Leviticus 23:24;  Numbers 29:1).

5. To The Feast Of Weeks Or First-Fruits ( Numbers 28:26).

6. To The Feast Of Tabernacles :

(a.) Its First Day ( Leviticus 23:35;  Numbers 29:12);

(b.) Its Last Day ( Leviticus 23:36).

7. As Introductory To The Enumeration Of These Feasts ( Leviticus 23:4), and as closing it ( Leviticus 23:7).

II. To the one great FAST, the Annual Day Of Atonement ( Leviticus 23:27;  Numbers 29:7). To the deep solemnities of "the Holy Convocation," whether of joy or of sorrow ("afflicting the soul," as in the last passage), one great feature was common, marked by the command, "Ye shall do no servile work therein" (see all the passages); or more fully in  Exodus 12:16, "No manner of work shall be done in them, save that which every man must eat, that only may be done of you." (Such as are curious about the Rabbinical opinions of what might be done, and what might not, on these occasions, may find them in Buxtorf's Synagoga Judaica, especially ch. 19; the joyous celebrations are described in ch. 21, and the expiatory in ch. 25, 26; see also Ugolini Thesaur. 4:988-1052). With this may be compared Strabo's statement (bk. 10), "This is a common practice both of Greeks and barbarians, to perform their sacred services with a festive cessation of labor." (See Sabbath).

International Standard Bible Encyclopedia [8]

kon - vō̇ - kā´shun  : A rendering for מקרא , miḳrā' chiefly in the frequent "Holy Convocation"; but the word is sometimes used alone, e.g.  Numbers 10:2;  Isaiah 1:13;  Isaiah 4:5 . On a holy convocation no work could be done. The phrase differs from "solemn assembly," which in the Pentateuch is only applied to the concluding festivals at the end of Passover and Tabernacles, while "Holy Convocation" is used of the Sabbath and all the great holy days of the Mosaic legislation.

The Nuttall Encyclopedia [9]

An assemblage of the English clergy, with little or no legislative power, summoned and prorogued by an archbishop under authority of the Crown; one under the Archbishop of Canterbury, held at Canterbury, and one under the Archbishop of York, held at York, consisting each of two bodies, an Upper of bishops, and an Under of lesser dignitaries and inferior clergy, in separate chambers, though they originally met in one.