A "reverse motorboat". Achieved by burying one's face between a supple set of buttcheeks and rapidly shaking the head from side to side. Optionally, one may purse the lips and blow out while botormoating to emulate the sound made by a motorboat's engine.
A word that has existed for centuries but has never been given a proper definition. Very hard to explain, but Bortor signifies a feeling that feels very strange. In other words, it just feels weird.