\Ep`i*tha*la"mi*um\, n.; pl. {Epithalamiums}, L. {Epithalamia}. [L., fr. Gr. ?, orig. an adj., nuptial; 'epi` upon, at + ? bride chamber.] A nuptial song, or poem in honor of the bride and bridegroom. The kind of poem which was called epithalamium . . . sung when the bride was led into her chamber. --B. Jonson.