RBF

RBF (countable and uncountable, plural RBFs)

1. (pathology, uncountable) Abbreviation of rat-bite fever.
2. (mathematics, countable) Abbreviation of radial basis function., a type of equation used to approximate a vector field, used in neural networks.
3. (countable) Abbreviation of resting bitch face.
   • 2013, Caren Duane, "This Is Just What I Look Like", The Dartmouth Mirror (Dartmouth College), 8 November 2013, page 8:

     "When I first met you I was scared of you."

     This phrase is commonplace for people with an RBF. They come to accept the natural state of their face as one that exudes feelings of anger, disgust or misery.

   • 2014, Andie Leeds, "Sass and the Milly", The Colonnade (Georgia College & State University), 10 October 2014, page 11:

     Her RBF has been with her ever since she was a baby, forcing her to fake a smile all the time so people would stop questioning her.

   • 2015, Angie Burkhart, "For some, smiling is too much work", The Coyote Chronicle (California State University, San Bernardino), Volume 52, Number 2, 27 April 2015, page 8:

     If you're looking for a more positive outlook on your RBF, here are a few things to consider: solicitors on campus are less likely to hound you with flyers, you may be less prone to smile wrinkles, and you probably have a very effective poker face.

   • For more examples of usage of this term, see Citations:RBF.

• FBR, FRB