The Collaborative International Dictionary of English v.0.48:

Rain \Rain\ (r[=a]n), n. [OE. rein, AS. regen; akin to OFries.
   rein, D. & G. regen, OS. & OHG. regan, Icel., Dan., & Sw.
   regn, Goth. rign, and prob. to L. rigare to water, to wet;
   cf. Gr. bre`chein to wet, to rain.]
   Water falling in drops from the clouds; the descent of water
   from the clouds in drops.
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         Rain is water by the heat of the sun divided into very
         small parts ascending in the air, till, encountering
         the cold, it be condensed into clouds, and descends in
         drops.                                   --Ray.
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         Fair days have oft contracted wind and rain. --Milton.
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   Note: Rain is distinguished from mist by the size of the
         drops, which are distinctly visible. When water falls
         in very small drops or particles, it is called mist;
         and fog is composed of particles so fine as to be not
         only individually indistinguishable, but to float or be
         suspended in the air. See Fog, and Mist.
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   Rain band (Meteorol.), a dark band in the yellow portion of
      the solar spectrum near the sodium line, caused by the
      presence of watery vapor in the atmosphere, and hence
      sometimes used in weather predictions.

   Rain bird (Zool.), the yaffle, or green woodpecker. [Prov.
      Eng.] The name is also applied to various other birds, as
      to Saurothera vetula of the West Indies.

   Rain fowl (Zool.), the channel-bill cuckoo (Scythrops
      Novae-Hollandiae) of Australia.

   Rain gauge, an instrument of various forms for measuring
      the quantity of rain that falls at any given place in a
      given time; a pluviometer; an ombrometer.

   Rain goose (Zool.), the red-throated diver, or loon. [Prov.
      Eng.]

   Rain prints (Geol.), markings on the surfaces of stratified
      rocks, presenting an appearance similar to those made by
      rain on mud and sand, and believed to have been so
      produced.

   Rain quail. (Zool.) See Quail, n., 1.

   Rain water, water that has fallen from the clouds in rain.
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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.
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   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.
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   3. (Geog.) A strait, or narrow sea, between two portions of
      lands; as, the British Channel.
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   4. That through which anything passes; a means of passing,
      conveying, or transmitting; as, the news was conveyed to
      us by different channels.
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            The veins are converging channels.    --Dalton.
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            At best, he is but a channel to convey to the
            National assembly such matter as may import that
            body to know.                         --Burke.
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   5. A gutter; a groove, as in a fluted column.
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   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.
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   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.
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   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.
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   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.
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   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.
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   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.
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   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.
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