The Collaborative International Dictionary
Diffarreation \Dif*far`re*a"tion\, n. [L. diffarreatio; dif- = farreum a spelt cake. See Confarreation.] A form of divorce, among the ancient Romans, in which a cake was used. See Confarreation.
Wiktionary
n. (context historical English) A form of divorce, among the Ancient Romans, in which a cake was used.
Wikipedia
In Ancient Rome, diffarreation (from Lat dif- + farreum, a spelt-cake) was a form of divorce in which a cake was used. Diffarreation was properly the dissolving of marriages contracted by confarreation, which were those of the pontifices. Festus says it was performed with a wheaten cake; and that it was called diffarreation from far, "wheat". Vigenère claims that confarreation and diffarreation are the same thing.