The Collaborative International Dictionary of English v.0.48:

Timber \Tim"ber\, v. t. [imp. & p. p. Timbered; p. pr. & vb.
   n. Timbering.]
   To furnish with timber; -- chiefly used in the past
   participle.
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         His bark is stoutly timbered.            --Shak.
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The Collaborative International Dictionary of English v.0.48:

Timbered \Tim"bered\, a.
   1. Furnished with timber; -- often compounded; as, a
      well-timbered house; a low-timbered house. --L'Estrange.
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   2. Built; formed; contrived. [R.] --Sir H. Wotton.
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   3. Massive, like timber. [Obs.]
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            His timbered bones all broken, rudely rumbled.
                                                  --Spenser.
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   4. Covered with growth timber; wooden; as, well-timbered
      land.
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WordNet (r) 3.0 (2006):

timbered
    adj 1: furnished with or made of wood or timbers; "timbered
           walls" [ant: untimbered]
    2: covered with growing timber; "thickly timbered ridges clothed
       with loblolly pine and holly"; "hills timbered up to their
       summits"

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "timbered":
   afforestational, arboreous, bosky, braky, bushy, copsy,
   dendrologic, forest, forestal, forested, reforestational, scrubby,
   shrubby, silvicultural, sylvan, wooded, woodland, woodsy, woody