"Buckwheat" is the wild haired character who played in "our gang" a 1930-1940 tv show.
"Beaver" is a slang word for a woman's vagina.
When the two are combined you can automatically get the mental image of a crazy haired vaginal area.
Wow trim that automatically comes to mind.
Billy: Did you go downtown last night?
Jim: Yah, but not worth braggin' man that shit was a buckwheat beaver, bro!
Billy: Are you serious?
Jim: Yeah, I'm still pullin pube's out of my teeth!
The term comes from other words that are already established. "Faux" which is defined as fake, imitation, ersatz.
Common slang word “Bia” which is the "G" rated way of calling a woman/man a bitch.
When putting the two together you are calling someone a "fake bitch." Many times this is used when someone is acting like they are someone/something they are not.
Kim: Dayum.....did you see the Prada bag that girl was wearing?
Lakisha: Her daddy bought that shit for her fauxbia ass. She has two kids and no man, and she aint even got a job.
Kim: Fo' real?! She is a fauxbia fo' sure!
Conversation that friends have that only they can understand, many times this is used when describing other surroundings when opposite sexes are around, a distinguished lingual that is understood by each party as a set meaning, language that can be many words or just a few that have meaning, this language can also be taps, hand shakes, winks, nods or other forms of body language
Bobby saw this real hot girl standing with her friend, looked over at James and flapped his arm as bro code, telling James he needs him as a wingman