diamond ring

plural diamond rings

1. Used other than figuratively or idiomatically: see diamond, ring.

   If that mocking bird don’t^([sic]) sing // Daddy’s going to buy me a diamond ring. // If that diamond ring don’t^([sic]) shine // Daddy’s going to buy me a bottle of wine.

   1907, Recreation, National Recreation Association, page 545

2. By extension, an engagement ring, usually one given by a man to a woman.

   “Delvin, a diamond ring means you are engaged to be married. I barely know you.”

   2006, Mary Slonaker, The Vinton House, page 37

   2 more examples

   If it were not a tradition that a woman shall accept from her fiance a diamond ring which the idiot cannot, in all probability, afford to give her — well, women would not accept them.

   1923, Peter Bernard Kyne, Never the Twain Shall Meet, page 19

   He frowned slightly, whether at the loss of a potential sale or the unnaturalness of a single woman standing beside a handsome man and not lusting after a diamond ring I couldn't be sure.

   2010, Juliet Blackwell, If Walls Could Talk: A Haunted Home Renovation Mystery

3. astronomyAn optical phenomenon visible during a moment of a solar eclipse when only a tiny part of the sun is not obscured by the moon, shining like a diamond in the ring of the sun’s corona.