A capital Greek letter commonly used to represent functions, surfaces, special sets, or decay constants in mathematics and physics.
Examples
Gamma function notation
\Gamma(n) = (n-1)!
Graph vertex set notation
\text{Let } \Gamma = (V,E) \text{ be a simple graph}
Special function relationship
\Gamma(z+1) = z\Gamma(z) \text{ for } z > 0