A derogatory term used to describe a person that is unaware of their ignorance on a certain topic despite insistence that they know what they are doing.

The term came from a Cornell University paper called "Unskilled and Unaware of It" by Justin Kruger and David Dunning. The paper describes that generally the more intelligent tend to underestimate their abilities because they know what they don't know. On the opposite side those the are ignorant tend to not know what they are talking about yet feel that they do.

In the paper an example is given of a man who smears lemon juice on his face because he thinks that it will keep cameras from seeing his face. After he robs a bank he is captured thanks to the bank camera footage. Even when shown the footage he could not comprehend how it didn't work. Hence the term lemon face.
"I'm not going to call a plumber honey because I can do it."
Wife responds, "Lemon face."

Paris Hilton pretty much trying to do anything.

Sarah Palin

Pete Griffin

Any noob that insists competence
by artivous13 January 4, 2010
Get the lemon face mug.
Term used to describe a middle-aged single woman, usually employed in a dead-end civil servant job. The lemon face has horrible people skills, is angry at the world, and with her life. She is the one who sits in her cubicle with a perpetual sour-puss look on her face. Lemon faces are typically employed by their respective civil service to be customer service reps.
I waited for 2 hours to renew my drivers licence but when I finally reached the counter, the lemon faced customer service rep told me I didn't have the right documents. Then she said "sucks to be you"
by Wordy McWorderson August 9, 2011
Get the lemon face mug.
the act of balling your face up at a sight that is repalsive or offending to the sences.
the smell in the bathroom made me lemon face.
by aries1992 February 27, 2010
Get the lemon face mug.
The face made when you are pissed to the point where you look like you just sucked a lemon dry.

The act of scrunching your face to the point where it is so ugly that your body counter acts it with pain.
Me: aye, you better chill out.
You: Why?,

Me: Bruh, that dude got a lemon face! He ain't playin.
You: Oh, shit RUN!!

#2.
Me: DAMN! whats that smell?!?!
you: SHIT!!! LEMON FACE!!
by Mickey McSlop February 27, 2010
Get the Lemon Face mug.
1) a girl who got a banging body but an ugly face

2) a girl whose face is squished all together giving her a big-ass-forehead effect
Damn Tara got a nice ass...but look at that Lemon Face.
by Jeri Shermaine December 8, 2008
Get the Lemon Face mug.
1. Term used to describe the unexpected or unwelcome delivery of any of the various male fluids onto a woman's face, resulting in a "scrunched up" facial expression as though the girl had just bitten into a sour lemon.

2. The permanent facial expression of Ellen Degenerates, as if she'd "just smelled poo" or caught a whiff of sour milk from an old carton in the refrigerator.
"She must have been really drunk, because when I climaxed she didn't make her usual lemon face".

"She started off with a few apple martinis, and ended up with a lemon face."

"She seemed to like the sex up until the climax, when she made a lemon face."
by Mark_J October 14, 2008
Get the Lemon Face mug.