The Collaborative International Dictionary of English v.0.48:

Channel \Chan"nel\, v. t. [imp. & p. p. Channeled, or
   Channelled; p. pr. & vb. n. Channeling, or
   Channelling.]
   1. To form a channel in; to cut or wear a channel or channels
      in; to groove.
      [1913 Webster]

            No more shall trenching war channel her fields.
                                                  --Shak.
      [1913 Webster]

   2. To course through or over, as in a channel. --Cowper.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Channel \Chan"nel\ (ch[a^]n"n[e^]l), n. [OE. chanel, canel, OF.
   chanel, F. chenel, fr. L. canalis. See Canal.]
   1. The hollow bed where a stream of water runs or may run.
      [1913 Webster]

   2. The deeper part of a river, harbor, strait, etc., where
      the main current flows, or which affords the best and
      safest passage for vessels.
      [1913 Webster]

   3. (Geog.) A strait, or narrow sea, between two portions of
      lands; as, the British Channel.
      [1913 Webster]

   4. That through which anything passes; a means of passing,
      conveying, or transmitting; as, the news was conveyed to
      us by different channels.
      [1913 Webster]

            The veins are converging channels.    --Dalton.
      [1913 Webster]

            At best, he is but a channel to convey to the
            National assembly such matter as may import that
            body to know.                         --Burke.
      [1913 Webster]

   5. A gutter; a groove, as in a fluted column.
      [1913 Webster]

   6. pl. [Cf. Chain wales.] (Naut.) Flat ledges of heavy
      plank bolted edgewise to the outside of a vessel, to
      increase the spread of the shrouds and carry them clear of
      the bulwarks.
      [1913 Webster]

   7. pl. official routes of communication, especially the
      official means by which information should be transmitted
      in a bureaucracy; as, to submit a request through
      channels; you have to go through channels.
      [PJC]

   8. a band of electromagnetic wave frequencies that is used
      for one-way or two-way radio communication; especially,
      the frequency bands assigned by the FTC for use in
      television broadcasting, and designated by a specific
      number; as, channel 2 in New York is owned by CBS.
      [PJC]

   9. one of the signals in an electronic device which receives
      or sends more than one signal simultaneously, as in
      stereophonic radios, records, or CD players, or in
      measuring equipment which gathers multiple measurements
      simultaneously.
      [PJC]

   10. (Cell biology) an opening in a cell membrane which serves
       to actively transport or allow passive transport of
       substances across the membrane; as, an ion channel in a
       nerve cell.
       [PJC]

   11. (Computers) a path for transmission of signals between
       devices within a computer or between a computer and an
       external device; as, a DMA channel.
       [PJC]

   Channel bar, Channel iron (Arch.), an iron bar or beam
      having a section resembling a flat gutter or channel.

   Channel bill (Zool.), a very large Australian cuckoo
      (Scythrops Nov[ae]hollandi[ae].

   Channel goose. (Zool.) See Gannet.
      [1913 Webster]

WordNet (r) 3.0 (2006):

channel
    n 1: a path over which electrical signals can pass; "a channel
         is typically what you rent from a telephone company" [syn:
         channel, transmission channel]
    2: a passage for water (or other fluids) to flow through; "the
       fields were crossed with irrigation channels"; "gutters
       carried off the rainwater into a series of channels under the
       street"
    3: a long narrow furrow cut either by a natural process (such as
       erosion) or by a tool (as e.g. a groove in a phonograph
       record) [syn: groove, channel]
    4: a deep and relatively narrow body of water (as in a river or
       a harbor or a strait linking two larger bodies) that allows
       the best passage for vessels; "the ship went aground in the
       channel"
    5: (often plural) a means of communication or access; "it must
       go through official channels"; "lines of communication were
       set up between the two firms" [syn: channel, communication
       channel, line]
    6: a bodily passage or tube lined with epithelial cells and
       conveying a secretion or other substance; "the tear duct was
       obstructed"; "the alimentary canal"; "poison is released
       through a channel in the snake's fangs" [syn: duct,
       epithelial duct, canal, channel]
    7: a television station and its programs; "a satellite TV
       channel"; "surfing through the channels"; "they offer more
       than one hundred channels" [syn: channel, television
       channel, TV channel]
    8: a way of selling a company's product either directly or via
       distributors; "possible distribution channels are wholesalers
       or small retailers or retail chains or direct mailers or your
       own stores" [syn: distribution channel, channel]
    v 1: transmit or serve as the medium for transmission; "Sound
         carries well over water"; "The airwaves carry the sound";
         "Many metals conduct heat" [syn: impart, conduct,
         transmit, convey, carry, channel]
    2: direct the flow of; "channel information towards a broad
       audience" [syn: channel, canalize, canalise]
    3: send from one person or place to another; "transmit a
       message" [syn: transmit, transfer, transport,
       channel, channelize, channelise]

Moby Thesaurus II by Grady Ward, 1.0:

248 Moby Thesaurus words for "channel":
   EDP, access, adolescent stream, adviser, aisle, alley,
   amateur band, ambulatory, announcer, annunciator, aperture,
   approach, approaches, aqueduct, arcade, arroyo, artery, authority,
   avenue, band, basin, beck, bed, bit, blowhole, bottleneck, bottom,
   bourn, braided stream, branch, brook, brooklet, burn, canal,
   canalization, canalize, carry, carve, chamfer, channelize, chisel,
   chute, citizens band, cloister, colonnade, communicant,
   communication, communication explosion, communication theory,
   communicator, conduct, conduit, connection, convey, corridor,
   corrugate, coulee, course, covered way, crack, creek, crick, crimp,
   cut, dado, data retrieval, data storage, debouch, decoding, defile,
   dike, direct, ditch, door, duct, egress,
   electronic data processing, emunctory, encoding, engrave,
   enlightener, entrenchment, entropy, escape, estuary, exhaust, exit,
   expert witness, fairway, ferry, floodgate, floor, flowing stream,
   flume, flute, fluviation, ford, fosse, frequency band, fresh,
   freshet, funnel, furrow, gallery, gash, gill, goffer, gossipmonger,
   gouge, grapevine, groove, ground, guide, gully, gutter, ha-ha,
   incise, informant, information center, information explosion,
   information medium, information theory, informer, inlet,
   interchange, intersection, interviewee, isthmus, junction, kennel,
   kill, lane, lazy stream, lead, loophole, meandering stream, means,
   medium, midchannel, midstream, millstream, moat, monitor,
   mouthpiece, moving road, narrow, narrows, navigable river, neck,
   newsmonger, noise, notifier, ocean bottom, opening, out, outcome,
   outfall, outgate, outgo, outlet, overpass, pass, passage,
   passageway, path, pipe, pipeline, pleat, plow, police band, pore,
   port, portico, press, public relations officer, publisher,
   put through, put through channels, rabbet, race, racing stream,
   radio, radio channel, railroad tunnel, redundancy, reporter, rifle,
   river, rivulet, road, run, rundle, runlet, runnel, rut, sally port,
   score, scratch, sea lane, seaway, ship route, shortwave band,
   signal, sike, siphon, slit, sluice, source, spill stream, spiracle,
   spokesman, spout, standard band, steamer track, strait, streak,
   stream, stream action, streamlet, striate, subterranean river,
   sunk fence, tap, television, teller, throat, tipster, tout,
   traject, trajet, transmit, trench, trough, tube, tunnel, underpass,
   vent, ventage, venthole, vomitory, wadi, watercourse, waterway,
   way, way out, weir, witness, wrinkle



The Jargon File (version 4.4.7, 29 Dec 2003):

channel
 n.

    [IRC] The basic unit of discussion on IRC. Once one joins a channel,
    everything one types is read by others on that channel. Channels are named
    with strings that begin with a ?#? sign and can have topic descriptions
    (which are generally irrelevant to the actual subject of discussion). Some
    notable channels are #initgame, #hottub, callahans, and #report. At times
    of international crisis, #report has hundreds of members, some of whom take
    turns listening to various news services and typing in summaries of the
    news, or in some cases, giving first-hand accounts of the action (e.g.,
    Scud missile attacks in Tel Aviv during the Gulf War in 1991).


The Free On-line Dictionary of Computing (30 December 2018):

channel
chat room
room

    (Or "chat room", "room", depending on the system in
   question) The basic unit of group discussion in chat systems
   like IRC.  Once one joins a channel, everything one types is
   read by others on that channel.  Channels can either be named
   with numbers or with strings that begin with a "#" sign and
   can have topic descriptions (which are generally irrelevant to
   the actual subject of discussion).

   Some notable channels are "#initgame", "#hottub" and
   "#report".  At times of international crisis, "#report" has
   hundreds of members, some of whom take turns listening to
   various news services and typing in summaries of the news, or
   in some cases, giving first-hand accounts of the action
   (e.g. Scud missile attacks in Tel Aviv during the Gulf War in
   1991).

   [Jargon File]

   (1998-01-25)


Easton's 1897 Bible Dictionary:

Channel
   (1.) The bed of the sea or of a river (Ps. 18:15; Isa. 8:7).

     (2.) The "chanelbone" (Job 31:22 marg.), properly "tube" or
   "shaft," an old term for the collar-bone.