Definition of "nugget"

Rough men brought pickle bottles full of nuggets. Mysterious dirty-looking calico bags were opened, disclosing small quantities of water-worn flaky gold, which had been washed out of the beds of rivers with a cradle.

1887, Harriet W. Daly, Digging, Squatting, and Pioneering Life in the Northern Territory of South Australia, page 146

By now, we hope you have said “no” to processed nuggets and fingers. Instead, how about taking some real chicken, tossing it with real eggs, a little tangy mustard, and a crunchy quinoa coating?

2014, Laurie David, The Family Cooks

As he has in superb works like “The Source” (based on the Afghanistan war logs leaked by Chelsea Manning) and “Sound From the Bench” (which set excerpts from Supreme Court proceedings), Hearne takes these found-text nuggets and gives them music that moves from lushly meditative to frenetic and obsessively repetitive […]

2023 July 10, Zachary Woolfe, “Review: Ted Hearne’s Sweet, Sad American Elegy”, in The New York Times‎

Jack stifled a smirk at the ensign's expressionless non-reaction. He'd been a nugget himself once, the new guy fresh from training.

2009, Nick Scipio, Nereids‎

We have previously said that the heuristic algorithms produce good nuggets for most classes and most λ values […]

2002, Data Mining: A Heuristic Approach, (Please provide the book title or journal name), page 93