From WordNet (r) 2.0 (August 2003) [wn]:
banns
n : a public announcement of a proposed marriage
From The Collaborative International Dictionary of English v.0.48 [gcide]: Banns \Banns\ (b[a^]nz), n. pl. [See Ban.] Notice of a proposed marriage, proclaimed in a church, or other place prescribed by law, in order that any person may object, if he knows of just cause why the marriage should not take place. [1913 Webster]