The eleventh month of the year, formerly known as November.
Brovember is a month dedicated to guys doing "guy things" such as watching football, going fishing, climbing mountains, and grillin.
During the month of Brovember, a man is exempt from feminine activities in order to strengthen the bonds between his bros.
"Sorry guys, no poker tonight. My wife wants me to go the opera, tonight."
"You serious dude? Today's the first of Brovember!"