ADJ.
formal, invited
VERB + BETROTHAL
announce
BETROTHAL + NOUN
week
noun
The act of betrothing.
marriage betrothal
formal betrothal
The fact of being betrothed; a mutual promise, engagement, or contract for a future marriage between two people.
noun — the act of becoming betrothed or engaged
noun — a mutual promise to marry
announce a betrothal
Eh? Hundreds of thousands of Yen plus betrothal gifts?
You are invited to a betrothal party a week from now.