The badge of a family, esp. of a family of the ancient feudal nobility. The most frequent form of the mon is circular, and it commonly consists of conventionalized forms from nature, flowers, birds, insects, the lightnings, the waves of the sea, or of geometrical symbolic figures; color is only a secondary character. It appears on lacquer and pottery, and embroidered on, or woven in, fabrics. The imperial chrysanthemum, the mon of the reigning family, is used as a national emblem. Formerly the mon of the shoguns of the Tokugawa family was so used.

A small coin.

Monetary unit of copper coins in pre-Tokugawa Japan; see Mon.

the symbol and colours of a clan or family

Abbreviation of Motor Octane Number.

Motor Octane Number. The earlier of two numerical systems for measuring gasoline octane. The octane number of a gasoline reflects its anti-knock properties, that is, its ability to withstand compression without detonating in an internal combustion engine.

Motor Octane Number, MON measures resistance of a fuel to knock at high speeds and high engine temperatures.

Acronym for "Motor Octane Number." See octane number.