Straining piece

from The Collaborative International Dictionary of English v.0.48

Straining \Strain"ing\,
   a. & n. from {Strain}.
   [1913 Webster]

   {Straining piece} (Arch.), a short piece of timber in a
      truss, used to maintain the ends of struts or rafters, and
      keep them from slipping. See Illust. of {Queen-post}.
      [1913 Webster]