The Collaborative International Dictionary of English v.0.48:

Thumbed \Thumbed\, a.
   1. Having thumbs.
      [1913 Webster]

   2. Soiled by handling.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Thumb \Thumb\, v. t. [imp. & p. p. Thumbed; p. pr. & vb. n.
   Thumbing.]
   1. To handle awkwardly. --Johnson.
      [1913 Webster]

   2. To play with the thumbs, or with the thumbs and fingers;
      as, to thumb over a tune.
      [1913 Webster]

   3. To soil or wear with the thumb or the fingers; to soil, or
      wear out, by frequent handling; also, to cover with the
      thumb; as, to thumb the touch-hole of a cannon.
      [1913 Webster]

            He gravely informed the enemy that all his cards had
            been thumbed to pieces, and begged them to let him
            have a few more packs.                --Macaulay.
      [1913 Webster]

WordNet (r) 3.0 (2006):

thumbed
    adj 1: (of pages) worn or soiled by thumb and fingers by
           frequent handling or turning; "well-thumbed pages of the
           dictionary"