kappa

noun

1. 1.

   The tenth letter of the Greek alphabet (K, κ), corresponding to the English letter K.

2. 2.

   (Statistics) A measure of agreement between raters, often referring to Cohen's kappa coefficient.

3. 3.

   (Biology) A type of immunoglobulin light chain found in antibodies.

4. 4.

   (Japanese folklore) A water demon or sprite in Japanese mythology, typically depicted as a humanoid creature with a turtle shell and a water-filled dish on its head.