A can of beer. Portmanteau of "brain" and "grenade". The "brain" comes from the alcohol's deleterious effects on the brain.
The "grenade" has multiple origins and meanings. In one sense, it compliments the "brain" in that the alcohol can have explosive effects on a user's behavior. In another sense-and why this term refers exclusively to canned beer-it comes from the similarity of the can and its consumption to hand grenades. Consider the metal shell containing a dangerous compound, the explosive potential, the common act of tossing one to a friend in need, the act of pulling a ring before use, etc.
The "grenade" has multiple origins and meanings. In one sense, it compliments the "brain" in that the alcohol can have explosive effects on a user's behavior. In another sense-and why this term refers exclusively to canned beer-it comes from the similarity of the can and its consumption to hand grenades. Consider the metal shell containing a dangerous compound, the explosive potential, the common act of tossing one to a friend in need, the act of pulling a ring before use, etc.
by Cpt. Drunkard December 08, 2010