Definition of "crackerjack"

crackerjack¹

adjective
comparative more crackerjack, superlative most crackerjack
1. Exceptionally fine or excellent; top-notch; high quality.
2. Expert, top-rated or high-performing.
noun
plural crackerjacks
1. An exceptionally fine or excellent thing or person.
2. An expert or top-rated individual (e.g., a marksman).

crackerjack²

adjective
not comparable
1. (US, slang) Referring to clothing items (pants, jersey, collar) that constitute the traditional blue uniform of the enlisted men of the US Navy.
noun
countable and uncountable, plural crackerjacks
1. (US, slang, in the plural) The traditional blue uniforms of the enlisted men of the US Navy.
2. (US, slang) A U.S. Navy sailor.
3. (US, uncountable) Popcorn candied in molasses-flavored caramel and peanuts.
  Quotations
  "Here, here's the popcorn man," Sid said as a vendor passed, pushing a cart. Sid bought a package of crackerjack and opened it while Mickey jumped up and down, unable to wait.
  1946, James T. Farrell, Bernard Clare, page 280