lozenge coach

noun1

1. •
   (historical) The coach of a dowager, having her coat of arms painted on a lozenge.

   • August 21 1746, Horace Walpole, letter to Sir Horace Mann I am retired hither like an old summer dowager ; only that I have no toad - eater to take the air with me in the back part of my lozenge - coach