(US, slang, in the plural) The traditional blue uniforms of the enlisted men of the US Navy. / (US, slang) A U.S. Navy sailor.

Exceptionally fine or excellent; top-notch; high quality. / Expert, top-rated or high-performing.

An exceptionally fine or excellent thing or person. / An expert or top-rated individual (e.g., a marksman).

(US, slang) Referring to clothing items (pants, jersey, collar) that constitute the traditional blue uniform of the enlisted men of the US Navy.

plural of crackerjack