A plant seed that jumps as a result of the movement of a moth larva which is developing inside it.
- ‘They had obtained a pair of Mexican jumping beans.’
- ‘Mexican jumping beans are grown in Mexico on a type of shrub.’
- ‘For more than half a century Mexican jumping beans have been sold in the United States.’
- ‘The movements of a jumping bean are actually caused by a caterpillar that lives inside the seed.’
- ‘The movement of a Mexican jumping bean will cause the tumbler to turn and toss about.’