petroglyph

from WordNet (r) 3.0 (2006)

petroglyph
    n 1: a carving or line drawing on rock (especially one made by
         prehistoric people)

from The Collaborative International Dictionary of English v.0.48

petroglyph \pet"ro*glyph`\ (p[e^]t"r[-o]*gl[i^]f`), n.
   A carving or drawing on rock, especially one made by
   prehistoric humans; called also a {petrograph}.
   [PJC]