kappa
noun
kap·pa ˈka-pə 
: the 10th letter of the Greek alphabet see Alphabet Table
Word History
Etymology
Middle English, from Greek, of Semitic origin; akin to Hebrew kaph
First Known Use
15th century, in the meaning defined above
Medical Definition
kappa
noun
kap·pa ˈkap-ə
: a cytoplasmic factor in certain paramecia that mediates production of paramecin and thereby makes the medium in which such microorganisms are grown toxic to members of strains not possessing the factor see paramecin