jumping bean
noun
: a seed of any of several Mexican shrubs (genera Sebastiania and Sapium) of the spurge family that tumbles about because of the movements of the larva of a small tortricid moth (Cydia saltitans synonym C. deshaisiana) inside it
Example Sentences
Recent Examples on the Web In the Shakespeare Studio, teacher Jo Gray lobs imaginary jumping beans into the mouths of children from Dr. Martin Luther King Jr. Elementary School. 
Jim Higgins, Milwaukee Journal Sentinel, 9 May 2018 Australia's Alison Wonderland will be a jumping bean behind the decks. Kat Bein, Billboard, 28 Feb. 2018 Still, the patients’ stories wriggled like jumping beans in my brain. Julie Rehmeyer, Slate Magazine, 12 June 2017
Jim Higgins, Milwaukee Journal Sentinel, 9 May 2018 Australia's Alison Wonderland will be a jumping bean behind the decks. Kat Bein, Billboard, 28 Feb. 2018 Still, the patients’ stories wriggled like jumping beans in my brain. Julie Rehmeyer, Slate Magazine, 12 June 2017 Word History
First Known Use
circa 1889, in the meaning defined above