The Collaborative International Dictionary of English v.0.48:

Church \Church\, v. t. [imp. & p. p. Churched; p. pr. & vb. n.
   Churching.]
   To bless according to a prescribed form, or to unite with in
   publicly returning thanks in church, as after deliverance
   from the dangers of childbirth; as, the churching of women.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Church \Church\ (ch[^u]rch), n. [OE. chirche, chireche, cherche,
   Scot. kirk, from AS. circe, cyrice; akin to D. kerk, Icel.
   kirkja, Sw. kyrka, Dan. kirke, G. kirche, OHG. chirihha; all
   fr. Gr. kyriako`n the Lord's house, fr. kyriako`s concerning
   a master or lord, fr. ky`rios master, lord, fr. ky^ros power,
   might; akin to Skr. [,c][=u]ra hero, Zend. [,c]ura strong,
   OIr. caur, cur, hero. Cf. Kirk.]
   [1913 Webster]
   1. A building set apart for Christian worship.
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   2. A Jewish or heathen temple. [Obs.] --Acts xix. 37.
      [1913 Webster]

   3. A formally organized body of Christian believers
      worshiping together. "When they had ordained them elders
      in every church." --Acts xiv. 23.
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   4. A body of Christian believers, holding the same creed,
      observing the same rites, and acknowledging the same
      ecclesiastical authority; a denomination; as, the Roman
      Catholic church; the Presbyterian church.
      [1913 Webster]

   5. The collective body of Christians.
      [1913 Webster]

   6. Any body of worshipers; as, the Jewish church; the church
      of Brahm.
      [1913 Webster]

   7. The aggregate of religious influences in a community;
      ecclesiastical influence, authority, etc.; as, to array
      the power of the church against some moral evil.
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            Remember that both church and state are properly the
            rulers of the people, only because they are their
            benefactors.                          --Bulwer.
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   Note: Church is often used in composition to denote something
         belonging or relating to the church; as, church
         authority; church history; church member; church music,
         etc.
         [1913 Webster]

   Apostolic church. See under Apostolic.

   Broad church. See Broad Church.

   Catholic church or Universal church, the whole body of
      believers in Christ throughout the world.

   Church of England, or English church, the Episcopal
      church established and endowed in England by law.

   Church living, a benefice in an established church.

   Church militant. See under Militant.

   Church owl (Zool.), the white owl. See Barn owl.

   Church rate, a tax levied on parishioners for the
      maintenance of the church and its services.

   Church session. See under Session.

   Church triumphant. See under Triumphant.

   Church work, work on, or in behalf of, a church; the work
      of a particular church for the spread of religion.

   Established church, the church maintained by the civil
      authority; a state church.
      [1913 Webster]

WordNet (r) 3.0 (2006):

church
    n 1: one of the groups of Christians who have their own beliefs
         and forms of worship [syn: church, Christian church]
    2: a place for public (especially Christian) worship; "the
       church was empty" [syn: church, church building]
    3: a service conducted in a house of worship; "don't be late for
       church" [syn: church service, church]
    4: the body of people who attend or belong to a particular local
       church; "our church is hosting a picnic next week"
    v 1: perform a special church rite or service for; "church a
         woman after childbirth"

Moby Thesaurus II by Grady Ward, 1.0:

97 Moby Thesaurus words for "church":
   Mass, adherents, affiliation, apostleship, bedtime prayer, body,
   branch, call, camp meeting, care of souls, church service,
   churchly, class, communion, community, compline, confession,
   connection, creed, cult, denomination, devotions, disciples,
   divine service, division, duty, evening devotions, evensong,
   exercises, faction, faith, fellowship, followers, group,
   holy orders, house of prayer, ism, lauds, liturgy, matins, meeting,
   morning devotions, night song, none, nones, novena, office,
   offshoot, order, organization, party, pastorage, pastoral care,
   pastorate, persuasion, praise meeting, prayer, prayer meeting,
   prayers, priesthood, priestship, prime, prime song, public worship,
   rabbinate, religious order, revival, revival meeting,
   sacred calling, schism, school, sect, sectarism, segment, service,
   sext, society, spiritual, tabernacle, temple, tent meeting,
   the church, the cloth, the desk, the ministry, the pulpit, tierce,
   undersong, variety, version, vesper, vespers, vigils, vocation,
   watch meeting, watch night, watch-night service



Easton's 1897 Bible Dictionary:

Church
   Derived probably from the Greek kuriakon (i.e., "the Lord's
   house"), which was used by ancient authors for the place of
   worship.

     In the New Testament it is the translation of the Greek word
   ecclesia, which is synonymous with the Hebrew _kahal_ of the Old
   Testament, both words meaning simply an assembly, the character
   of which can only be known from the connection in which the word
   is found. There is no clear instance of its being used for a
   place of meeting or of worship, although in post-apostolic times
   it early received this meaning. Nor is this word ever used to
   denote the inhabitants of a country united in the same
   profession, as when we say the "Church of England," the "Church
   of Scotland," etc.

     We find the word ecclesia used in the following senses in the
   New Testament: (1.) It is translated "assembly" in the ordinary
   classical sense (Acts 19:32, 39, 41).

     (2.) It denotes the whole body of the redeemed, all those whom
   the Father has given to Christ, the invisible catholic church
   (Eph. 5:23, 25, 27, 29; Heb. 12:23).

     (3.) A few Christians associated together in observing the
   ordinances of the gospel are an ecclesia (Rom. 16:5; Col. 4:15).

     (4.) All the Christians in a particular city, whether they
   assembled together in one place or in several places for
   religious worship, were an ecclesia. Thus all the disciples in
   Antioch, forming several congregations, were one church (Acts
   13:1); so also we read of the "church of God at Corinth" (1 Cor.
   1:2), "the church at Jerusalem" (Acts 8:1), "the church of
   Ephesus" (Rev. 2:1), etc.

     (5.) The whole body of professing Christians throughout the
   world (1 Cor. 15:9; Gal. 1:13; Matt. 16:18) are the church of
   Christ.

     The church visible "consists of all those throughout the world
   that profess the true religion, together with their children."
   It is called "visible" because its members are known and its
   assemblies are public. Here there is a mixture of "wheat and
   chaff," of saints and sinners. "God has commanded his people to
   organize themselves into distinct visible ecclesiastical
   communities, with constitutions, laws, and officers, badges,
   ordinances, and discipline, for the great purpose of giving
   visibility to his kingdom, of making known the gospel of that
   kingdom, and of gathering in all its elect subjects. Each one of
   these distinct organized communities which is faithful to the
   great King is an integral part of the visible church, and all
   together constitute the catholic or universal visible church." A
   credible profession of the true religion constitutes a person a
   member of this church. This is "the kingdom of heaven," whose
   character and progress are set forth in the parables recorded in
   Matt. 13.

     The children of all who thus profess the true religion are
   members of the visible church along with their parents. Children
   are included in every covenant God ever made with man. They go
   along with their parents (Gen. 9:9-17; 12:1-3; 17:7; Ex. 20:5;
   Deut. 29:10-13). Peter, on the day of Pentecost, at the
   beginning of the New Testament dispensation, announces the same
   great principle. "The promise [just as to Abraham and his seed
   the promises were made] is unto you, and to your children" (Acts
   2:38, 39). The children of believing parents are "holy", i.e.,
   are "saints", a title which designates the members of the
   Christian church (1 Cor. 7:14). (See BAPTISM.)

     The church invisible "consists of the whole number of the
   elect that have been, are, or shall be gathered into one under
   Christ, the head thereof." This is a pure society, the church in
   which Christ dwells. It is the body of Christ. it is called
   "invisible" because the greater part of those who constitute it
   are already in heaven or are yet unborn, and also because its
   members still on earth cannot certainly be distinguished. The
   qualifications of membership in it are internal and are hidden.
   It is unseen except by Him who "searches the heart." "The Lord
   knoweth them that are his" (2 Tim. 2:19).

     The church to which the attributes, prerogatives, and promises
   appertaining to Christ's kingdom belong, is a spiritual body
   consisting of all true believers, i.e., the church invisible.

     (1.) Its unity. God has ever had only one church on earth. We
   sometimes speak of the Old Testament Church and of the New
   Testament church, but they are one and the same. The Old
   Testament church was not to be changed but enlarged (Isa.
   49:13-23; 60:1-14). When the Jews are at length restored, they
   will not enter a new church, but will be grafted again into
   "their own olive tree" (Rom. 11:18-24; comp. Eph. 2:11-22). The
   apostles did not set up a new organization. Under their ministry
   disciples were "added" to the "church" already existing (Acts
   2:47).

     (2.) Its universality. It is the "catholic" church; not
   confined to any particular country or outward organization, but
   comprehending all believers throughout the whole world.

     (3.) Its perpetuity. It will continue through all ages to the
   end of the world. It can never be destroyed. It is an
   "everlasting kindgdom."