1.  crackerjack(n = noun.person) jimdandy, jimhickey - someone excellent of their kind; "he's a jimdandy of a soldier"
is a kind of apotheosis, ideal, nonesuch, nonpareil, nonsuch, paragon, saint

2.  crackerjack(n = noun.artifact) jimdandy, jimhickey - something excellent of its kind; "the bike was a jimdandy"
is a kind of thing

1.  An individual of marked ability or excellence, esp. in some sport; as, he is a crackajack at tennis. [Webster 1913 Suppl.]

2.  A preparation of popped corn, candied and pressed into small cakes. The name Cracker Jack(TM) is now a trademark for a similar confection. [Webster 1913 Suppl.]

3.  something excellent of its kind. [WordNet 1.5]

   Of marked ability or excellence. [Webster 1913 Suppl.]

crackerjack, adj. & n. US sl.
--adj. exceptionally fine or expert.
--n. an exceptionally fine thing or person.

N  proficient, expert, adept, dab, dabster, crackerjack, connoisseur, master, master hand, prima donna, first fiddle, top gun, chef de cuisine, top sawyer, protagonist, past master, mahatma, picked man, medallist, prizeman, veteran, old stager, old campaigner, old soldier, old file, old hand, man of business, man of the world, nice hand, good hand, clean hand, practiced hand, experienced eye, experienced hand, marksman, good shot, dead shot, crack shot, ropedancer, funambulist, acrobat, cunning man, conjuror, wizard, genius, mastermind, master head, master spirit, cunning blade, sharp blade, sharp fellow, jobber, cracksman, politician, tactician, strategist, pantologist, admirable Crichton, Jack of all trades, prodigy of learning.