A cold or cough that is caught by sharing anything by lip with another man.

Often confused with the organic chemistry compound of the same name, a bromonium a person who is consistently a bro, short for brother. They're with you to the end, and aren't fake or dishonest with you. The second part of the word comes from harmonium, which is a pump organ that makes a very long, continuous sound using very little effort. A true bro is a bromonium, because they don't pretend to be a bro temporarily or only in certain situations.