engagement ring
US /ɪnˈɡeɪdʒ.mənt ˌrɪŋ/
UK /ɪnˈɡeɪdʒ.mənt ˌrɪŋ/

1.
a ring given by a man to a woman to mark their engagement to be married
:
•
He proposed with a beautiful diamond engagement ring.
•
She proudly showed off her new engagement ring.