3 terms were found starting with the letter k.
 

Keystone Species
A species that is central to its ecosystem, whose continued well-being is vital to the existence of other species in that ecosystem.
 
Kuznets Curve
An "inverted U" relationship between a country's per capita income and the degree of inequality in its income distribution. In other words, the distribution of income first worsens during the course of economic growth and then later improves.
 
Kwashiorkor
Severe malnutrition, especially in children, characterized by anemia, edema (swelling of tissue), potbelly, depigmentation of the skin, and loss of hair or change in hair color.