lozenge

Etymology

From Middle English losenge, from Old French losenge (“rhombus”), from Old French *lose (“flag-stone”), from Vulgar Latin *lausa.

noun

1. (shapes, heraldry) A quadrilateral with sides of equal length (rhombus), having two acute and two obtuse angles.
   Wherein the decussis is made within a longilaterall square, with opposite angles, acute and obtuse at the intersection; and so upon progression making a Rhombus or Lozenge figuration …. 1658, Sir Thomas Browne, The Garden of Cyrus, Folio Society, published 2007, page 167
   How the junior partner of Hobbs and Dobbs leads her smiling to the carriage with the lozenge upon it, and the fat wheezy coachman! 1848, William Makepeace Thackeray, chapter 9, in Vani8ty Fair
   The floor is constructed from marble lozenges and triangles of every imaginable hue: yellow and pink and all manner of mottled and blotched shades, framed in white. 2004, Richard Fortey, The Earth, Folio Society, published 2011, page 14
2. A small tablet (originally diamond-shaped) or medicated sweet used to ease a sore throat.

verb

1. (transitive) To form into the shape of a lozenge.
2. (transitive) To mark or emblazon with a lozenge.