Etymology

Noun

1. A quadrilateral shape with sides of equal length, having two acute and two obtuse angles; a diamond.
   • 1658: 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 — Sir Thomas Browne, The Garden of Cyrus (Folio Society 2007, p. 167)
2. A rhombus.
3. A small tablet (originally diamond-shaped) or medicated sweet used to ease a sore throat.

Synonyms

• (quadrilateral): diamond (informal), rhomb, rhombus
• (medicated sweet): pastille, throat pastille, troche