What is Contra Bonos Mores?

Legal Definition
Against good morals.

2. All contracts contra bonos mores, are illegal. These are reducible to Several classes, namely, those which are, 1. lncentive to crime. A claim cannot be sustained, therefore, on. a bond for compounding a crime; as, for example, a prosecution for perjury; 2 Wils. R. 341, 447; or for procuring a pardon. A distinction has been made between a contract made as a reparation for an injury to the honor of a female, and one which is to be the reward of future illicit cohabitation; the former is good and valid, and the latter is illegal. 3 Burr. 1568; 1 Bligh's R. 269.

3. - 2. Indecent or mischievous consideration. An obligation or engagement prejudicial to the feelings of a third party; or offensive to decency or morality; or which has a tendency to mischievous or pernicious consequences, is void. Cowp. 729; 4 Campb. R. 152; Rawle's R. 42; 1 B. & A. 683; 4 Esp. Cas. 97; 16 East R. 150; Vide Wagers.

4. - 3. Gaming. The statutes against gaming render all contracts made for the purpose of gaming, void. Vide Gaming; Unlawful; Void.
-- Bouviers Law Dictionary
Legal Definition
"Against good morals". Contracts so made are generally illegal and unenforceable.
Legal Definition
Against good morals. Contracts contra bonos mores are void
-- Black's Law Dictionary
Legal Definition
Against good morals.
-- Ballentine's Law Dictionary