Derives from the word "bro". Describes a concentrated group of bros in a certain area, particularly at some sort of brotastic concert such as STS9 or Pretty Lights, as well as many house parties. Experiencing Hibroshima can be quite petrifying. In addition to multitudes of 59-50 hats, plaid shorts and solid-colored t-shirts or polo shirts, hibroshima usually involves a disproportionate amount of PBR, various bro-whoops and much fist-pounding and chest bopping. Can also be described as a brofest.
I had to leave that party last night, it turned into total Hibroshima.
by sugaree31 September 14, 2010