1. 
[syn: ailing, indisposed, peaked(p), poorly(p), sickly, unwell, under the weather, seedy]
2.  having or rising to a peak; 
- Example: "the peaked ceiling"
- Example: "the island's peaked hills"
The Collaborative International Dictionary of English v.0.48:
Peaked \Peaked\ (p[=e]kt or p[=e]k"[e^]d), a.
   1. Pointed; ending in a point; as, a peaked roof.
      [1913 Webster]
   2. (Oftener p[=e]k"[e^]d) Sickly; not robust. [Colloq.]
      [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Peak \Peak\, v. i. [imp. & p. p. Peaked (p[=e]kt); p. pr. &
   vb. n. Peaking.]
   1. To rise or extend into a peak or point; to form, or appear
      as, a peak.
      [1913 Webster]
            There peaketh up a mighty high mount. --Holand.
      [1913 Webster]
   2. Hence: To achieve a maximum of numerical value, intensity
      of activity, popularity, or other characteristic, followed
      by a decline; as, the stock market peaked in January; his
      performance as a pitcher peaked in 1990; sales of the XTX
      model peaked at 20,000 per year.
      [PJC]
   3. To acquire sharpness of figure or features; hence, to look
      thin or sickly. "Dwindle, peak, and pine." --Shak.
      [1913 Webster]
   4. [Cf. Peek.] To pry; to peep slyly. [archaic] --Shak.
      [1913 Webster]
   Peak arch (Arch.), a pointed or Gothic arch.
      [1913 Webster]
WordNet (r) 3.0 (2006):
peaked
    adj 1: somewhat ill or prone to illness; "my poor ailing
           grandmother"; "feeling a bit indisposed today"; "you look
           a little peaked"; "feeling poorly"; "a sickly child"; "is
           unwell and can't come to work" [syn: ailing,
           indisposed, peaked(p), poorly(p), sickly,
           unwell, under the weather, seedy]
    2: having or rising to a peak; "the peaked ceiling"; "the
       island's peaked hills"
Moby Thesaurus II by Grady Ward, 1.0:
68 Moby Thesaurus words for "peaked":
   acicular, acuminate, acute, attenuated, cachectic, cadaverous,
   capped, corpselike, crested, crowned, cuspidate, debilitated,
   drained, emacerated, emaciate, emaciated, enervated, exhausted,
   failing, feeble, frail, haggard, headed, healthless, hollow-eyed,
   in poor health, infirm, invalid, jejune, languishing, marantic,
   marasmic, moribund, pale, peaking, peaky, pinched, plumed, poor,
   puny, reduced, reduced in health, run-down, sharp, shriveled, sick,
   sickly, skeletal, starved, starveling, tabetic, tabid, tipped,
   topped, underfed, undernourished, unhealthy, unsound,
   valetudinarian, valetudinary, wasted, weakened, weakly, weazeny,
   with low resistance, withered, wizened, wraithlike