Definition

Noun: 1. A seed of certain Mexican shrubs (genus Sebastiana): This seed appears to move or jump on its own because it contains the living larva of a small moth (Cydia saltitans). The movements of the larva inside cause the seed to jerk, roll, or tumble.

Usage Examples

• The Mexican jumping bean fascinated the children as it skittered across the table.
• In the gift shop, they sold Mexican jumping beans as a novelty item.
• The apparent motion of a Mexican jumping bean is actually caused by an insect larva trapped inside.

Advanced Usage

• The term is often used to describe something that exhibits sudden, jerky, or unpredictable motion, similar to the bean's movement.
  • The old washing machine bounced around the laundry room like a Mexican jumping bean during the spin cycle.

Variants and Related Words

• Jumping bean (n): A more general term, though it most commonly refers to the Mexican variety.
• Sebastiana (n): The botanical genus of the shrubs that produce these seeds.

Synonyms

• Tumbling seed (descriptive, but not a common synonym)

Notes on Meaning

• A Mexican jumping bean is not a true bean (legume) but the seed capsule of a shrub. Its primary and most distinctive characteristic is its autonomous-seeming movement, which is a biological phenomenon rather than a magical one.

Noun

1. seed of Mexican shrubs of the genus Sebastiana containing the larva of a moth whose movements cause the bean to jerk or tumble