Broefficient Share definition Flag The "Bro-Coefficient", i.e., the degree of bros at a given gathering. "Dude, the broefficient of this party is off the charts! There's like 12 guys for every one girl. Let's get the hell out of here!" Broefficient by Kevin M. G. June 29, 2008 0 0 Get merch Get the Broefficient mug. Buy Now — $32.95 See more merch