There are multiple definitions:

1. dynamic Bayesian network(English)

   • BIC, BN, CPD, CPDAG, DAG
   • Model(ing)

2. downbeat nystagmus(English)

   • one of the most common pathological types of central nystagmus. Generally due to cerebellar dysfunction, e.g., because of a neurodegenerative disease
   • GEN, UBN
   • Ophthalmology, Brain (dys)function
   • https://doi.org…ztebl.2011.0197