A high school teacher, usually an English teacher, who has been teaching children that are smarter than she is for so long that she now hates kids entirely and is completely jaded with the educational system.

Usually wears an awkward mix of ugly solid colored sweaters with dress pants, and suffers horribly from the "muffin top effect". Researchers, after studying this phenomenon extensively, have dubbed it as the "Brennan mushroom top effect", due to the extreme nature of the situation.

If your teacher is discovered to be a Brennan, switch classes immediately, or commit suicide. Teaching style usually involves 10-12 activities in a class that are never completed, a never-ending grammar practice, and reading stories that the Brennan itself cannot understand. This is coupled with random F's on any and all assignments, and students who pass a Brennan's class are proven to be better at Chinese than English(at least, students who have never studied Chinese are. Students with prior Chinese knowledge are found to forget that as well).

All attempts to fight a Brennan have been met with failure. It is speculated that only a pizzly bear, Bear Grylls, Beowulf, or Barack Obama Himself could fight one off succesfully. However, due to the rarity of these mythical creatures, this hypothesis has never been tested.
"Dude, why is our English teacher such a bitch?"

"Because she's a Brennan, duh"
by TheConsequence January 24, 2010
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14 year old douche flute that spends his days masturbating and watching clown porn. he is completely obsessed with runescape and black cocks
Dude that loser is such a brennan
by Gopherman69 March 01, 2017
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A total pervert who no one cares about. Also a total idiot. May seem hot or sexy but he'll break your heart in one second. Brennan is a awful person.
Brennan:
#idiot
#sexy
#heartbreaker
#pervert
#awful
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A Person (usually boy) who loves to pretend he looks exactly like every main character of every anime that he deems (with bad taste) to be "cool".

A Brennan usually looks like Carrot Top
Look at that Brennan going around saying he looks like naruto.
by Paul Byrd September 02, 2008
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A Brennan is usually the type of person who has good friends, and typically sticks with them, however some people get annoyed with the amount of times they call.
“OMG I love Brennan he is so sweet
Yeah but why does he keep calling me???”
by Akakakakkakakakkakakkakaka October 01, 2018
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