Definition of jumping bean in US English:

jumping bean

noun

  • A plant seed that jumps as a result of the movement of a moth larva which is developing inside it.

    Affected seeds are found in several plants of the family Euphorbiaceae, in particular the Mexican plant Sebastiana pavoniana, the seeds of which can contain larvae of the moth Cydia saltitans

    • ‘For more than half a century Mexican jumping beans have been sold in the United States.’
    • ‘Mexican jumping beans are grown in Mexico on a type of shrub.’
    • ‘They had obtained a pair of Mexican jumping beans.’
    • ‘The movement of a Mexican jumping bean will cause the tumbler to turn and toss about.’
    • ‘The movements of a jumping bean are actually caused by a caterpillar that lives inside the seed.’

Pronunciation

jumping bean

/ˈjəmpiNG ˌbēn//ˈdʒəmpɪŋ ˌbin/