noun: (pathology, uncountable) Abbreviation of rat-bite fever. [Spirillosis, or sodoku, transmitted by the gram-negative coiled rod Spirillum minus, found in Asia.]
noun: (mathematics, countable) Abbreviation of radial basis function., a type of equation used to approximate a vector field, used in neural networks.
noun: (countable, uncountable) Abbreviation of resting bitch face. [(slang, vulgar, derogatory) An angry or unpleasant look that does not accurately reflect the way a person is feeling or that the person assumes when not consciously controlling their expression.]