from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Slang Of excellent quality or ability; fine.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Exceptionally fine or excellent; top-notch; high quality.
- adj. Expert, top-rated or high-performing.
- adj. 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.
- n. An exceptionally fine or excellent thing or person.
- n. An expert or top-rated individual (e.g., a marksman)
- n. The traditional blue uniforms of the enlisted men of the US Navy.
- n. A sailor.
from the GNU version of the Collaborative International Dictionary of English
- n. An individual of marked ability or excellence, esp. in some sport.
- n. A preparation of popped corn, candied and pressed into small cakes. The name Cracker Jack(TM) is now a trademark for a similar confection.
- n. something excellent of its kind.
- adj. Of marked ability or excellence.
from The Century Dictionary and Cyclopedia
- n. See crackajack.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. someone excellent of their kind
- n. something excellent of its kind
Probably from crack, first-rate + jack.(American Heritage® Dictionary of the English Language, Fourth Edition)