Definition of "FN"

I know your purse say D and G, holdin' my FN

2020, Moneybagg Yo, Match My Fly

A FN diagnosis, on the other hand, can give a patient the illusion of good health (and the patient will not get the necessary treatment).

2015 July 24, Krzysztof J. Cios, Dat T. Nguyen, “Data mining and data visualization”, in Susan J Henly, editor, Routledge International Handbook of Advanced Quantitative Methods in Nursing Research, Routledge, page 316

From the optics of fairness, we care more about FPs than FNs because it's more unfair to put an innocent person in prison than it is to leave a guilty person in the streets.

2021 March 26, Serg Masís, Interpretable Machine Learning with Python: Learn to build interpretable high-performance models with hands-on real-world examples, Packt Publishing Ltd, page 291