espousal

1. 1. A betrothal.
   2. A wedding ceremony.
2. Adoption of an idea or a cause.

[Middle English espousaille, from sing. of Old French espousailles, betrothal, from Latin spōnsālia, from neuter pl. of spōnsālis, of a betrothal, from spōnsus, spouse. See spouse.]

noun

1. The act or condition of being pledged to marry: betrothal, engagement, troth. See marriage/unmarried.
2. The act or ceremony by which two people become husband and wife: bridal, marriage, nuptial (often used in plural), spousal (often used in plural), wedding. See marriage/unmarried.
3. A ready taking up of something: adoption, embracement. See accept/reject, give/take/reciprocity.

The noun has 3 meanings:

Meaning #1: the act of becoming betrothed or engaged
  Synonym: betrothal

Meaning #2: archaic terms for a wedding or wedding feast
  Synonym: bridal

Meaning #3: the act of accepting with approval; favorable reception
  Synonyms: adoption, acceptance, acceptation