The nerd face emoji is a yellow, neutral face with closed eyes, a small, frowning mouth, and raised eyebrows, shown with a pair of large, round eyeglasses with thick, black frames.
It is often used to convey a sense of intelligence, studiousness, or expertise, and it can be used to show that you are intelligent or knowledgeable, or that you are interested in or passionate about a particular subject. It can also be used to express a sense of studiousness or diligence, or to show that you are feeling studious or focused.
Some platforms have redesigned nerd face over time to not have buck teeth, perhaps in acknowledgement of the harm this imagery may cause. Google, Facebook, and JoyPixels originally featured designs with buck teeth but have since changed (or completely removed) the teeth on nerd face.
Apple, Twitter, Microsoft, Samsung, WhatsApp, and other platforms still use designs for this emoji that include buck teeth.
Nerd Face was approved as part of Unicode 8.0 in 2015 and added to Emoji 1.0 in 2015.
U+1F913
? Nerd face