Nugget

The term "nugget" is Colonial military slang for a pilot trainee.

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

Nuggets in the post-Exodus Fleet

The first class of nuggets moments into their first day of training (Act of Contrition).

Kara Thrace is assigned the task of flight instructor to train a batch of potential Viper pilots after 13 (including Flat Top) are killed in a freak accident (Act of Contrition).

This first group of eight nuggets includes Louanne "Kat" Katraine", Brendan "Hotdog" Costanza, and Donald "Chuckles" Perry.

As Galactica lacks flight simulators, Starbuck trains the first nugget group in actual Viper Mark IIs.

Attrition of this group begins when Chuckles dies while attacking a Cylon tylium refinery (The Hand of God). Over a year later, Katraine dies from radiation poisoning (The Passage). Of this original nugget group, Costanza is among the few known survivors.

When Pegasus joins the Fleet, flight simulators are available to train nuggets without risking damage or loss of fighters. Brent Baxton and Joseph Clark are two nuggets that complete their training this way (Scar).

Months after the flight from New Caprica, Racetrack jokingly remarks that she wants to have sex with a nugget, thus indicating that new pilots are still trained (The Woman King). The most recently inducted nuggets are newly-promoted Ensign Diana Seelix (Dirty Hands) and Fleet enlistee Samuel Anders (Crossroads, Part I).

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".