What is "bromian"

Usage examples of "bromian".

But since every bud in the wreath of pleasure Ye owe to the sister Hours, No stinted cups, in a formal measure, The Bromian law makes ours.

For the temples tall, and the statues fair, And the feasts of the Gods are holiest there, The feasts of Immortals, the chaplets of flowers And the Bromian mirth at the coming of spring, And the musical voices that fill the hours, And the dancing feet of the Maids that sing!