anything (action or spoken) done by a boy that us girls thinks is stupid.
He broke up with her for another girl, he's always creating havoc with his boyism.
by E. M. February 26, 2008
the disease that boys are born with that mentally impair their thinking. concerning mostly sports, girlfriends and alcohol.
Will was diagnosed with boyism when he continuly fucked shit up with his ex-girlfreind Katlyn, like seeing her than decideing he didnt want to two hours later!
by coolchicks November 12, 2009