Nugget

The term "nugget" is Colonial military jargon for a pilot trainee. The definition of a nugget is a lump of raw precious metal, something ready to be molded. Alternatively, a small rounded piece of food ("Blood and Chrome" (deleted scene)).

Upon successful completion of flight and weapons training, nuggets join the Fleet squadrons as rooks.

Notes

• When the first class of nuggets begins training aboard Galactica, they wear rank insignia of petty officer, 1st class. In "Scar" and "Dirty Hands", they wear those of lieutenants, junior grade, but are addressed as ensigns. So far no distinct ensign rank insignia has been shown. The lack of a distinct ensign's insignia is likely a costuming error or simple necessity, absent any clear decision by the executive production team.
• Chief Tyrol notes that one has to be an officer to fly Vipers when he pins ensign's insignia on Seelix before she reports for flight training, suggesting either a change in policy or a retcon.
• The Original Series analogue to this term is "first orbit cadet".