The Collaborative International Dictionary of English v.0.48:

Bald \Bald\ (b[add]ld), a. [OE. balled, ballid, perh. the p. p.
   of ball to reduce to the roundness or smoothness of a ball,
   by removing hair. [root]85. But cf. W. bali whiteness in a
   horse's forehead.]
   1. Destitute of the natural or common covering on the head or
      top, as of hair, feathers, foliage, trees, etc.; as, a
      bald head; a bald oak.
      [1913 Webster]

            On the bald top of an eminence.       --Wordsworth.
      [1913 Webster]

   2. Destitute of ornament; unadorned; bare; literal.
      [1913 Webster]

            In the preface to his own bald translation.
                                                  --Dryden.
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   3. Undisguised. " Bald egotism." --Lowell.
      [1913 Webster]

   4. Destitute of dignity or value; paltry; mean. [Obs.]
      [1913 Webster]

   5. (Bot.) Destitute of a beard or awn; as, bald wheat.
      [1913 Webster]

   6. (Zool.)
      (a) Destitute of the natural covering.
      (b) Marked with a white spot on the head; bald-faced.
          [1913 Webster]

   Bald buzzard (Zool.), the fishhawk or osprey.

   Bald coot (Zool.), a name of the European coot (Fulica
      atra), alluding to the bare patch on the front of the
      head.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

baldheaded \bald"head`ed\, bald-headed \bald"-head`ed\, a.
   Having a bald head; lacking hair on all or most of the scalp;
   -- alsp called bald and bald-pated; as, a bald-headed
   gentleman.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

bald
    adj 1: with no effort to conceal; "a barefaced lie" [syn:
           bald, barefaced]
    2: lacking hair on all or most of the scalp; "a bald pate"; "a
       bald-headed gentleman" [syn: bald, bald-headed, bald-
       pated]
    3: without the natural or usual covering; "a bald spot on the
       lawn"; "bare hills" [syn: bald, denuded, denudate]
    v 1: grow bald; lose hair on one's head; "He is balding already"

Moby Thesaurus II by Grady Ward, 1.0:

106 Moby Thesaurus words for "bald":
   Spartan, acomous, ascetic, austere, bald-headed, bare, bare-ass,
   beardless, blank, candid, clean-shaven, clear, cleared, clipped,
   colorless, common, commonplace, cropped, depilous, direct,
   disclosed, dry, dull, exposed, frank, free, glabrous,
   gymnosophical, hairless, homely, homespun, in native buff,
   in puris naturalibus, in the altogether, in the buff, in the raw,
   lackluster, lean, lifeless, lusterless, matter-of-fact, naked,
   natural, naturistic, neat, nude, nudist, open, open as day,
   open to all, overt, peeled, plain, plain-speaking, plain-spoken,
   polled, prosaic, prosing, prosy, pure, raw, revealed, rustic,
   severe, shaven, sheared, simple, simple-speaking, smooth,
   smooth-faced, smooth-shaven, sober, spare, stark, stark-naked,
   straightforward, tonsured, unadorned, unadulterated, unaffected,
   unarrayed, unclassified, unclogged, unclosed, uncolored,
   uncomplicated, uncovered, undecked, undecorated, undressed,
   unembellished, unfurbished, ungarnished, unhidden, unimaginative,
   unobstructed, unornamented, unpoetical, unrestricted,
   unsophisticated, unstopped, untrimmed, unvarnished, wide-open,
   with nothing on, without a stitch