Cracker Jack

US: (krak′ər jak′)

WordReference Random House Unabridged Dictionary of American English © 2025

Crack′er Jack′, [Trademark.]

1. Food, Trademarks a confection of caramel-coated popcorn and peanuts.

crack•er•jack  (krak′ər jak′), [Informal.]
n. 

1. a person or thing that shows marked ability or excellence.

adj. 

2. of marked ability;
   exceptionally fine.

Also, crackajack. 

• 1890–95, American; earlier crackajack, rhyming compound based on crack (adjective, adjectival); -a- as in blackamoor; jack¹ in sense "chap, fellow''