The Collaborative International Dictionary of English v.0.48:

Shaps \Shaps\ (sh[a^]ps), n. pl. [Shortened fr. chaparajos. Cf.
   Chaps.]
   Chaparajos. [Western U. S.]

         A pair of gorgeous buckskin shaps, embroidered up the
         sides and adorned with innumerable ermine skins. --The
                                                  Century.
   [Webster 1913 Suppl.]