Lambda (Λ λ) is the 11th letter of the Greek alphabet and has a numeric value of 30.
The lower-case letter λ is used as a symbol for:
- In physics and radio (and other fields), the wavelength (λ) of a wave.
- In biology, the Lambda phage virus.
- In Lambda calculus and by extension some programming languages, lambda notation is used to define functions anonymously.
- The language Unlambda is made up completely of lambdas, but they cannot be stored, hence the un-
- Gay pride (explanations for this usage vary).