A kind of egg · also called albumen, glair, egg whites

About
Egg white is the clear, protein-rich liquid inside an egg, weighing slightly more than water for the same volume.
Egg white has a density of about 8.6 pounds per gallon (1.03 grams per milliliter), which is roughly three percent denser than fresh water. Because it is about 90 percent water and 10 percent dissolved protein, it flows and fills volume much like water does. Whole egg yolks contain significant fat and are slightly less dense, meaning whites pack more mass into the same space. An average large chicken egg yields about 1.1 fluid ounces (33 milliliters) of white.
From Wikipedia
Egg white is the clear liquid contained within an egg. In chickens, it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg.
Read more on Wikipedia →Text from Wikipedia’s “Egg white” article, CC BY-SA 4.0.
One cup weighs
8.6 oz (244 g)
Quick answer
One US cup of egg whites weighs about 8.6 ounces (244 grams). That makes it slightly heavier than an equal measure of water.
Typical figures, the same ones every comparison on the site uses; real ones vary.
More like egg white
Compare it
Next to anything: a person, a car, another egg.