The Collaborative International Dictionary of English v.0.48:

Lean-faced \Lean"-faced`\, a.
   1. Having a thin face.
      [1913 Webster]

   2. (Typog.) slender or narrow; -- said of type the letters of
      which have thin lines, or are unusually narrow in
      proportion to their height. --W. Savage.
      [1913 Webster]