epithalamium

noun2

1. •
   A song or poem celebrating a marriage.

   • He has wittily redone a tardy epithalamium and some nursery rhymes ("Three blind eunuchs"), and deftly catches the cozy lawnfuls of plastic dwarfs and flamingos, outside the kenneled people. — 1976
2. •
   A song in praise of the bride or bridegroom