stands for cave man bubbles word salad. a jumble of incoherent words that make the person sound like they're talking like 1) a cave man 2) in bubbles 3) in word salad (which is just a bunch of mixed up words not making sense)
RM: 'yeah...she went, mmm, okay, that today, or yesterday, so annoying. you and me go later.'
L: 'whoa...you should get some sleep, you're not making any sense. You're talking in CMBWS'