n. a disgusting and annoying person. (Use with caution. From bowel movement. A way of calling a person a shit. Derogatory.)
The guy's a real BM. A total pain.The new guy has to be the world's worst BM.
BM
noun a BMW car. Further abbreviated from BEEMER rather than directly from the BMW brand name; the car is a status-symbol, and seeking to sound evermore casual about its name is simple snobbery UK, 1999