A more thorough explanation:

Definition: Mainour (may-nuhr) is a historical term that refers to a stolen item that is found in the possession of a thief. The word comes from the Law French word "manier," which means "to handle."

Under common law, if a thief was caught with a mainour, they could be arrested and tried without an indictment. The term is also spelled "manour" or "meinour" and is sometimes referred to as "mannopus" or "manuopus."

One example of a mainour might be a stolen piece of jewelry found in the pocket of a thief. Another example could be a stolen painting discovered in the home of a suspected art thief.

These examples illustrate the definition of mainour because they both involve stolen items that are found in the possession of someone who is believed to have taken them. In both cases, the mainour could be used as evidence in a trial against the thief.