Mildly insulting phrase denotes silly behaviour, actions or thoughts usually attributed to a child or immature person.
"Don't get angry at your little bro., he did not mean to pull your hair, he is a two-year old bird brain"
by Muyuna December 11, 2004
by aymeryia March 04, 2009
by Supercords June 06, 2012
by JQPublic April 05, 2010
really dumb and ugly males who scratch their testicles al day long and like to interact with other bird brains. Hobbies include xbox,shooting,talkin about xbox and talkin about shooting...NOW NOW NOW NOW
by non bird brain January 27, 2011