The Collaborative International Dictionary of English v.0.48:

Rawboned \Raw"boned`\ (-b[=o]nd`), a.
   Having little flesh on the bones; gaunt. --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

rawboned
    adj 1: having a lean and bony physique; "a rawboned cow hand"

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "rawboned":
   angular, bony, flat, flat-chested, fleshless, gangling, gangly,
   gaunt, gawky, lank, lanky, lean, lean-fleshed, lean-looking,
   meager, scraggy, scrawny, skeletal, skinny, spare, spidery,
   spindling, spindly, thin-bellied, thin-fleshed, twiggy, undersized,
   underweight