ep·i·tha·la·mi·um 
(ĕp′ə-thə-lāmē-əm) or ep·i·tha·la·mi·on (-ən)
(ĕp′ə-thə-lāmē-əm) or ep·i·tha·la·mi·on (-ən)n. pl. ep·i·tha·la·mi·ums or ep·i·tha·la·mi·a (-mē-ə)
A lyric ode in honor of a bride and bridegroom.
[Latin, from Greek epithalamion, from neuter of epithalamios, of a wedding : epi-, epi- + thalamos, bridal chamber.]