The Collaborative International Dictionary of English v.0.48:

Trim \Trim\, a. [Compar. Trimmer; superl. Trimmest.] [See
   Trim, v. t.]
   Fitly adjusted; being in good order., or made ready for
   service or use; firm; compact; snug; neat; fair; as, the ship
   is trim, or trim built; everything about the man is trim; a
   person is trim when his body is well shaped and firm; his
   dress is trim when it fits closely to his body, and appears
   tight and snug; a man or a soldier is trim when he stands
   erect.
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         With comely carriage of her countenance trim.
                                                  --Spenser.
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         So deemed I till I viewed their trim array
         Of boats last night.                     --Trench.
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The Collaborative International Dictionary of English v.0.48:

Trimmer \Trim"mer\, n.
   1. One who trims, arranges, fits, or ornaments.
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   2. One who does not adopt extreme opinions in politics, or
      the like; one who fluctuates between parties, so as to
      appear to favor each; a timeserver.
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            Thus Halifax was a trimmer on principle. --Macaulay.
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   3. An instrument with which trimming is done.
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   4. (Arch.) A beam, into which are framed the ends of headers
      in floor framing, as when a hole is to be left for stairs,
      or to avoid bringing joists near chimneys, and the like.
      See Illust. of Header.
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   5. (Coal Storage) An apparatus used for piling the coal in
      gradually increasing piles made by building up at the
      point of the cone or top of the prism.
      [Webster 1913 Suppl.]
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WordNet (r) 3.0 (2006):

trimmer
    n 1: a worker who thins out and trims trees and shrubs;
         "untouched by the pruner's axe" [syn: pruner, trimmer]
    2: a machine that trims timber
    3: capacitor having variable capacitance; used for making fine
       adjustments [syn: trimmer, trimming capacitor]
    4: joist that receives the end of a header in floor or roof
       framing in order to leave an opening for a staircase or
       chimney etc. [syn: trimmer, trimmer joist]