crackerjack

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Of excellent quality or ability; fine.

from The Century Dictionary.

• noun See crackajack.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Slang Of marked ability or excellence.
• noun Slang An individual of marked ability or excellence, esp. in some sport.
• noun United States A preparation of popped corn, candied and pressed into small cakes. The name Cracker Jack(TM) is now a trademark for a similar confection.
• noun something excellent of its kind.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Exceptionally fine or excellent; top-notch; high quality.
• adjective Expert, top-rated or high-performing.
• adjective US, slang Referring to clothing items (pants, jersey, collar) that comprise the traditional blue uniform of the enlisted men of the US Navy, following the sailor uniform worn by Sailor Jack on boxes of Cracker Jack snacks.
• noun An exceptionally fine or excellent thing or person.
• noun An expert or top-rated individual (e.g., a marksman)
• noun US, slang, in the plural The traditional blue uniforms of the enlisted men of the US Navy.
• noun US, slang A sailor.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun someone excellent of their kind
• noun something excellent of its kind