RBF


Also found in: Medical, Acronyms, Wikipedia.

RBF

rude slang An abbreviation for "resting bitch face," a perpetually angry or sullen look on one's face when it is "resting" or neutral (not intentionally making any expression). This phrase is typically only used to describe women. I'm not mad, I just have RBF. She looks grumpy but she just has RBF. She's actually very approachable!