Yours, Etc.: Origins and Uses of 8 Sign-Offs
1570s, from Latin bipartitus "divided," past participle of bipartire "to divide into two parts," from bi- (see bi-) + partitus, past participle of partiri "to divide" (see part (v.)).
bipartite bi·par·tite (bī-pär'tīt')adj. Consisting of two parts or divisions.