Ten·ter, n.  A machine or frame for stretching cloth by means of hooks, called tenter-hooks, so that it may dry even and square.
  Tenter ground, a place where tenters are erected.
  Tenter-hook, a sharp, hooked nail used for fastening cloth on a tenter.
  To be on the tenters, To be on the tenter-hooks or To be on tenterhooks, to be on the stretch; to be in distress, uneasiness, or suspense. --Hudibras.